[AIX] Python binding enablement and gcc support (#21934)

### Description
Enabling python binding and gcc support for AIX.



### Motivation and Context
Code changes in this PR contains:
1. python binding enablement
2. gcc building support


Below are list of files and the description.

1. cmake/CMakeLists.txt
[gcc building support] -no-unused-function compiler flag addition for
IBMClang
2. cmake/external/eigen.cmake
[gcc building support] AIX check for applying the AIX patch
3. cmake/onnxruntime_python.cmake
[python binding ] putting NOT AIX check for -Xlinker
4. cmake/onnxruntime_unittests.cmake
[gcc building support] Fix for gtest behavior. Check the comment .
[python binding ] using -Wl,-brtl for linking
onnxruntime_providers_shared in test_execution_provider
5. cmake/patches/eigen/eigen-aix.patch
[gcc building support] In AIX gcc, we are hitting
__builtin_cpu_supports("mma") which is not supported yet. So patching
code for this method . Patched code will check for P10 Processor at
run-time and based on that routine will be set.
6. onnxruntime/python/onnxruntime_validation.py
[python binding ] Adding AIX check in check_distro_info()
7. onnxruntime/test/providers/cpu/generator/random_test.cc
[gcc building support] updating previous check for AIX , along with
clang. So in case of gcc, else block will hit.
8. onnxruntime/test/python/onnxruntime_test_python.py
[python binding ] powerpc check on platform.processor()
9. setup.py
[python binding ] Adding AIX check for list of libs.

cmake/CMakeLists.txt

@@ -1041,6 +1041,9 @@ function(onnxruntime_set_compile_flags target_name)
         #external/protobuf/src/google/protobuf/arena.h:445:18: error: unused parameter 'p'
         target_compile_options(${target_name} PRIVATE "-Wno-unused-parameter")
       endif()
+      if (CMAKE_CXX_COMPILER_ID STREQUAL "IBMClang")
+        target_compile_options(${target_name} PRIVATE "-Wno-unused-function")
+      endif()
       target_compile_definitions(${target_name} PUBLIC -DNSYNC_ATOMIC_CPP11)
       onnxruntime_add_include_to_target(${target_name} nsync::nsync_cpp)
     endif()

cmake/external/eigen.cmake

@@ -3,11 +3,20 @@ if (onnxruntime_USE_PREINSTALLED_EIGEN)
     file(TO_CMAKE_PATH ${eigen_SOURCE_PATH} eigen_INCLUDE_DIRS)
     target_include_directories(eigen INTERFACE ${eigen_INCLUDE_DIRS})
 else ()
-    FetchContent_Declare(
-        eigen
-        URL ${DEP_URL_eigen}
-        URL_HASH SHA1=${DEP_SHA1_eigen}
-    )
+    if(CMAKE_SYSTEM_NAME MATCHES "AIX")
+        FetchContent_Declare(
+            eigen
+            URL ${DEP_URL_eigen}
+            URL_HASH SHA1=${DEP_SHA1_eigen}
+            PATCH_COMMAND ${Patch_EXECUTABLE} --binary --ignore-whitespace -p1 < ${PROJECT_SOURCE_DIR}/patches/eigen/eigen-aix.patch
+        )
+    else()
+        FetchContent_Declare(
+            eigen
+            URL ${DEP_URL_eigen}
+            URL_HASH SHA1=${DEP_SHA1_eigen}
+        )
+    endif()
 
     FetchContent_Populate(eigen)
     set(eigen_INCLUDE_DIRS  "${eigen_SOURCE_DIR}")

cmake/onnxruntime_python.cmake

@@ -117,7 +117,9 @@ elseif(UNIX)
   if (onnxruntime_ENABLE_EXTERNAL_CUSTOM_OP_SCHEMAS)
     set(ONNXRUNTIME_SO_LINK_FLAG "-Xlinker --version-script=${ONNXRUNTIME_ROOT}/python/version_script_expose_onnx_protobuf.lds -Xlinker --gc-sections")
   else()
-    set(ONNXRUNTIME_SO_LINK_FLAG "-Xlinker --version-script=${ONNXRUNTIME_ROOT}/python/version_script.lds -Xlinker --gc-sections")
+    if (NOT CMAKE_SYSTEM_NAME MATCHES "AIX")
+      set(ONNXRUNTIME_SO_LINK_FLAG "-Xlinker --version-script=${ONNXRUNTIME_ROOT}/python/version_script.lds -Xlinker --gc-sections")
+    endif()
   endif()
 else()
   set(ONNXRUNTIME_SO_LINK_FLAG "-DEF:${ONNXRUNTIME_ROOT}/python/pybind.def")
@@ -224,7 +226,9 @@ elseif (APPLE)
     BUILD_WITH_INSTALL_RPATH TRUE
     INSTALL_RPATH_USE_LINK_PATH FALSE)
 else()
-  set_property(TARGET onnxruntime_pybind11_state APPEND_STRING PROPERTY LINK_FLAGS " -Xlinker -rpath=\\$ORIGIN")
+  if (NOT CMAKE_SYSTEM_NAME MATCHES "AIX")
+     set_property(TARGET onnxruntime_pybind11_state APPEND_STRING PROPERTY LINK_FLAGS " -Xlinker -rpath=\\$ORIGIN")
+  endif()
 endif()
 
 if (onnxruntime_ENABLE_EXTERNAL_CUSTOM_OP_SCHEMAS)

cmake/onnxruntime_unittests.cmake

@@ -915,6 +915,15 @@ if (MSVC AND onnxruntime_ENABLE_STATIC_ANALYSIS)
 target_compile_options(onnxruntime_test_all PRIVATE  "/analyze:stacksize 131072")
 endif()
 
+#In AIX + gcc compiler ,crash is observed with the usage of googletest EXPECT_THROW,
+#because some needed symbol is garbaged out by linker.
+#So, fix is to exports the symbols from executable.
+#Another way is to use -Wl,-bkeepfile for each object file where EXPECT_THROW is used like below
+#target_link_options(onnxruntime_test_all PRIVATE "-Wl,-bkeepfile:CMakeFiles/onnxruntime_test_all.dir${TEST_SRC_DIR}/framework/tensor_test.cc.o")
+if (CMAKE_SYSTEM_NAME MATCHES "AIX" AND CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  set_target_properties(onnxruntime_test_all PROPERTIES ENABLE_EXPORTS 1)
+endif()
+
 # the default logger tests conflict with the need to have an overall default logger
 # so skip in this type of
 target_compile_definitions(onnxruntime_test_all PUBLIC -DSKIP_DEFAULT_LOGGER_TESTS)
@@ -1766,7 +1775,12 @@ if (NOT onnxruntime_MINIMAL_BUILD AND NOT onnxruntime_EXTENDED_MINIMAL_BUILD
 
   onnxruntime_add_shared_library_module(test_execution_provider ${test_execution_provider_srcs})
   add_dependencies(test_execution_provider onnxruntime_providers_shared onnx ${ABSEIL_LIBS})
-  target_link_libraries(test_execution_provider PRIVATE onnxruntime_providers_shared ${ABSEIL_LIBS} Boost::mp11)
+  if (CMAKE_SYSTEM_NAME MATCHES "AIX")
+    target_link_options(test_execution_provider PRIVATE -Wl,-brtl -lonnxruntime_providers_shared)
+    target_link_libraries(test_execution_provider PRIVATE ${ABSEIL_LIBS} Boost::mp11)
+  else()
+    target_link_libraries(test_execution_provider PRIVATE onnxruntime_providers_shared ${ABSEIL_LIBS} Boost::mp11)
+  endif()
   target_include_directories(test_execution_provider PRIVATE $<TARGET_PROPERTY:onnx,INTERFACE_INCLUDE_DIRECTORIES>)
   target_include_directories(test_execution_provider PRIVATE $<TARGET_PROPERTY:onnxruntime_common,INTERFACE_INCLUDE_DIRECTORIES>)
   target_include_directories(test_execution_provider PRIVATE ${ONNXRUNTIME_ROOT} ${CMAKE_CURRENT_BINARY_DIR} ${ORTTRAINING_ROOT})