WIP: Fix for m68k #1483

Job	Run time
duplicates	4s
build (libgccjit.so, master, --mini-tests)	9m 9s
build (libgccjit.so, master, --std-tests)	9m 8s
build (libgccjit.so, master, --test-libcore)	9m 1s
build (libgccjit.so, master, --extended-rand-tests)	13m 36s
build (libgccjit.so, master, --extended-regex-example-tests)	10m 9s
build (libgccjit.so, master, --extended-regex-tests)	22m 52s
build (libgccjit.so, master, --test-successful-rustc --nb-parts 2 --current-part 0)	23m 59s
build (libgccjit.so, master, --test-successful-rustc --nb-parts 2 --current-part 1)	26m 16s
build (libgccjit_without_int128.so, master-without-128bit-integers, --mini-tests)	8m 58s
build (libgccjit_without_int128.so, master-without-128bit-integers, --std-tests)	9m 3s
build (libgccjit_without_int128.so, master-without-128bit-integers, --test-libcore)	9m 12s
build (libgccjit_without_int128.so, master-without-128bit-integers, --extended-rand-tests)	13m 9s
build (libgccjit_without_int128.so, master-without-128bit-integers, --extended-regex-example-tests)	10m 22s
build (libgccjit_without_int128.so, master-without-128bit-integers, --extended-regex-tests)	23m 0s
build (libgccjit_without_int128.so, master-without-128bit-integers, --test-successful-rustc --nb-...	23m 3s
build (libgccjit_without_int128.so, master-without-128bit-integers, --test-successful-rustc --nb-...	18m 26s
	3h 59m 27s

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