Minor memory leak in device and platform

[keichi]

There is a minor memory leak due to a circular reference between the device and platform classes. Following is the output from an
address sanitizer build:

=================================================================
==768033==ERROR: LeakSanitizer: detected memory leaks

Indirect leak of 64 byte(s) in 1 object(s) allocated from:
    #0 0x7ff9a75ce587 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cc:104
    #1 0x55828d1cb806 in __gnu_cxx::new_allocator<neosycl::sycl::device>::allocate(unsigned long, void const*) /usr/include/c++/9/ext/new_allocator.h:114
    #2 0x55828d1c71aa in std::allocator_traits<std::allocator<neosycl::sycl::device> >::allocate(std::allocator<neosycl::sycl::device>&, unsigned long) /usr/include/c++/9/bits/alloc_traits.h:443
    #3 0x55828d1c1b5f in std::_Vector_base<neosycl::sycl::device, std::allocator<neosycl::sycl::device> >::_M_allocate(unsigned long) /usr/include/c++/9/bits/stl_vector.h:343
    #4 0x55828d1bc86b in void std::vector<neosycl::sycl::device, std::allocator<neosycl::sycl::device> >::_M_realloc_insert<neosycl::sycl::device const&>(__gnu_cxx::__normal_iterator<neosycl::sycl::device*, std::vector<neosycl::sycl::device, std::allocator<neosycl::sycl::device> > >, neosycl::sycl::device const&) /usr/include/c++/9/bits/vector.tcc:440
    #5 0x55828d1b67d4 in std::vector<neosycl::sycl::device, std::allocator<neosycl::sycl::device> >::push_back(neosycl::sycl::device const&) /usr/include/c++/9/bits/stl_vector.h:1195
    #6 0x55828d1b7dfe in void neosycl::sycl::initial_platform_builder::add<neosycl::sycl::detail::device_impl_host>(neosycl::sycl::platform&) /usr/local/include/neoSYCL/sycl/detail/platform.hpp:102
    #7 0x55828d1a9be8 in neosycl::sycl::platform::register_all_devices() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:123
    #8 0x55828d1ad9d5 in __static_initialization_and_destruction_0 /usr/local/include/neoSYCL/sycl/detail/platform.hpp:43
    #9 0x55828d1adc87 in _GLOBAL__sub_I__ZN7neosycl4sycleqERKNS0_8platformES3_ /home/keichi/Projects/veo-sycl-bench/sycl/gemm/gemm.cpp:67
    #10 0x55828d1d222c in __libc_csu_init (/home/keichi/Projects/veo-sycl-bench/sycl/gemm/a.out+0x3222c)

Indirect leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7ff9a75ce587 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cc:104
    #1 0x55828d1b7a4e in neosycl::sycl::device neosycl::sycl::initial_platform_builder::get<neosycl::sycl::detail::device_impl_host>() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:93
    #2 0x55828d1b7d8e in void neosycl::sycl::initial_platform_builder::add<neosycl::sycl::detail::device_impl_host>(neosycl::sycl::platform&) /usr/local/include/neoSYCL/sycl/detail/platform.hpp:100
    #3 0x55828d1a9be8 in neosycl::sycl::platform::register_all_devices() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:123
    #4 0x55828d1ad9d5 in __static_initialization_and_destruction_0 /usr/local/include/neoSYCL/sycl/detail/platform.hpp:43
    #5 0x55828d1adc87 in _GLOBAL__sub_I__ZN7neosycl4sycleqERKNS0_8platformES3_ /home/keichi/Projects/veo-sycl-bench/sycl/gemm/gemm.cpp:67
    #6 0x55828d1d222c in __libc_csu_init (/home/keichi/Projects/veo-sycl-bench/sycl/gemm/a.out+0x3222c)

Indirect leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7ff9a75ce587 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cc:104
    #1 0x55828d1b7a4e in neosycl::sycl::device neosycl::sycl::initial_platform_builder::get<neosycl::sycl::detail::device_impl_host>() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:93
    #2 0x55828d1b210b in neosycl::sycl::initial_platform_builder::create() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:106
    #3 0x55828d1a9bd2 in neosycl::sycl::platform::register_all_devices() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:118
    #4 0x55828d1ad9d5 in __static_initialization_and_destruction_0 /usr/local/include/neoSYCL/sycl/detail/platform.hpp:43
    #5 0x55828d1adc87 in _GLOBAL__sub_I__ZN7neosycl4sycleqERKNS0_8platformES3_ /home/keichi/Projects/veo-sycl-bench/sycl/gemm/gemm.cpp:67
    #6 0x55828d1d222c in __libc_csu_init (/home/keichi/Projects/veo-sycl-bench/sycl/gemm/a.out+0x3222c)

Indirect leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7ff9a75ce587 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cc:104
    #1 0x55828d1b212f in neosycl::sycl::initial_platform_builder::create() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:107
    #2 0x55828d1a9bd2 in neosycl::sycl::platform::register_all_devices() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:118
    #3 0x55828d1ad9d5 in __static_initialization_and_destruction_0 /usr/local/include/neoSYCL/sycl/detail/platform.hpp:43
    #4 0x55828d1adc87 in _GLOBAL__sub_I__ZN7neosycl4sycleqERKNS0_8platformES3_ /home/keichi/Projects/veo-sycl-bench/sycl/gemm/gemm.cpp:67
    #5 0x55828d1d222c in __libc_csu_init (/home/keichi/Projects/veo-sycl-bench/sycl/gemm/a.out+0x3222c)

Indirect leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7ff9a75ce587 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cc:104
    #1 0x55828d1ca19e in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<neosycl::sycl::detail::platform_impl*>(neosycl::sycl::detail::platform_impl*) /usr/include/c++/9/bits/shared_ptr_base.h:625
    #2 0x55828d1c580e in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<neosycl::sycl::detail::platform_impl*>(neosycl::sycl::detail::platform_impl*, std::integral_constant<bool, false>) /usr/include/c++/9/bits/shared_ptr_base.h:636
    #3 0x55828d1be2cc in std::__shared_ptr<neosycl::sycl::detail::platform_impl, (__gnu_cxx::_Lock_policy)2>::__shared_ptr<neosycl::sycl::detail::platform_impl, void>(neosycl::sycl::detail::platform_impl*) /usr/include/c++/9/bits/shared_ptr_base.h:1125
    #4 0x55828d1b7856 in std::shared_ptr<neosycl::sycl::detail::platform_impl>::shared_ptr<neosycl::sycl::detail::platform_impl, void>(neosycl::sycl::detail::platform_impl*) /usr/include/c++/9/bits/shared_ptr.h:139
    #5 0x55828d1a9884 in neosycl::sycl::platform::platform(neosycl::sycl::detail::platform_impl*) /usr/local/include/neoSYCL/sycl/detail/platform.hpp:71
    #6 0x55828d1b2157 in neosycl::sycl::initial_platform_builder::create() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:107
    #7 0x55828d1a9bd2 in neosycl::sycl::platform::register_all_devices() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:118
    #8 0x55828d1ad9d5 in __static_initialization_and_destruction_0 /usr/local/include/neoSYCL/sycl/detail/platform.hpp:43
    #9 0x55828d1adc87 in _GLOBAL__sub_I__ZN7neosycl4sycleqERKNS0_8platformES3_ /home/keichi/Projects/veo-sycl-bench/sycl/gemm/gemm.cpp:67
    #10 0x55828d1d222c in __libc_csu_init (/home/keichi/Projects/veo-sycl-bench/sycl/gemm/a.out+0x3222c)

Indirect leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7ff9a75ce587 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cc:104
    #1 0x55828d1c6e9c in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<neosycl::sycl::detail::device_impl*>(neosycl::sycl::detail::device_impl*) /usr/include/c++/9/bits/shared_ptr_base.h:625
    #2 0x55828d1c18c0 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<neosycl::sycl::detail::device_impl*>(neosycl::sycl::detail::device_impl*, std::integral_constant<bool, false>) /usr/include/c++/9/bits/shared_ptr_base.h:636
    #3 0x55828d1b9d02 in std::__shared_ptr<neosycl::sycl::detail::device_impl, (__gnu_cxx::_Lock_policy)2>::__shared_ptr<neosycl::sycl::detail::device_impl, void>(neosycl::sycl::detail::device_impl*) /usr/include/c++/9/bits/shared_ptr_base.h:1125
    #4 0x55828d1b490c in std::shared_ptr<neosycl::sycl::detail::device_impl>::shared_ptr<neosycl::sycl::detail::device_impl, void>(neosycl::sycl::detail::device_impl*) /usr/include/c++/9/bits/shared_ptr.h:139
    #5 0x55828d1aeae4 in neosycl::sycl::device::device(neosycl::sycl::detail::device_impl*, neosycl::sycl::platform*) /usr/local/include/neoSYCL/sycl/device.hpp:99
    #6 0x55828d1b7a73 in neosycl::sycl::device neosycl::sycl::initial_platform_builder::get<neosycl::sycl::detail::device_impl_host>() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:93
    #7 0x55828d1b7d8e in void neosycl::sycl::initial_platform_builder::add<neosycl::sycl::detail::device_impl_host>(neosycl::sycl::platform&) /usr/local/include/neoSYCL/sycl/detail/platform.hpp:100
    #8 0x55828d1a9be8 in neosycl::sycl::platform::register_all_devices() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:123
    #9 0x55828d1ad9d5 in __static_initialization_and_destruction_0 /usr/local/include/neoSYCL/sycl/detail/platform.hpp:43
    #10 0x55828d1adc87 in _GLOBAL__sub_I__ZN7neosycl4sycleqERKNS0_8platformES3_ /home/keichi/Projects/veo-sycl-bench/sycl/gemm/gemm.cpp:67
    #11 0x55828d1d222c in __libc_csu_init (/home/keichi/Projects/veo-sycl-bench/sycl/gemm/a.out+0x3222c)

Indirect leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7ff9a75ce587 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cc:104
    #1 0x55828d1c6e9c in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<neosycl::sycl::detail::device_impl*>(neosycl::sycl::detail::device_impl*) /usr/include/c++/9/bits/shared_ptr_base.h:625
    #2 0x55828d1c18c0 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<neosycl::sycl::detail::device_impl*>(neosycl::sycl::detail::device_impl*, std::integral_constant<bool, false>) /usr/include/c++/9/bits/shared_ptr_base.h:636
    #3 0x55828d1b9d02 in std::__shared_ptr<neosycl::sycl::detail::device_impl, (__gnu_cxx::_Lock_policy)2>::__shared_ptr<neosycl::sycl::detail::device_impl, void>(neosycl::sycl::detail::device_impl*) /usr/include/c++/9/bits/shared_ptr_base.h:1125
    #4 0x55828d1b490c in std::shared_ptr<neosycl::sycl::detail::device_impl>::shared_ptr<neosycl::sycl::detail::device_impl, void>(neosycl::sycl::detail::device_impl*) /usr/include/c++/9/bits/shared_ptr.h:139
    #5 0x55828d1aeae4 in neosycl::sycl::device::device(neosycl::sycl::detail::device_impl*, neosycl::sycl::platform*) /usr/local/include/neoSYCL/sycl/device.hpp:99
    #6 0x55828d1b7a73 in neosycl::sycl::device neosycl::sycl::initial_platform_builder::get<neosycl::sycl::detail::device_impl_host>() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:93
    #7 0x55828d1b210b in neosycl::sycl::initial_platform_builder::create() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:106
    #8 0x55828d1a9bd2 in neosycl::sycl::platform::register_all_devices() /usr/local/include/neoSYCL/sycl/detail/platform.hpp:118
    #9 0x55828d1ad9d5 in __static_initialization_and_destruction_0 /usr/local/include/neoSYCL/sycl/detail/platform.hpp:43
    #10 0x55828d1adc87 in _GLOBAL__sub_I__ZN7neosycl4sycleqERKNS0_8platformES3_ /home/keichi/Projects/veo-sycl-bench/sycl/gemm/gemm.cpp:67
    #11 0x55828d1d222c in __libc_csu_init (/home/keichi/Projects/veo-sycl-bench/sycl/gemm/a.out+0x3222c)

SUMMARY: AddressSanitizer: 248 byte(s) leaked in 7 allocation(s).