New test fail with MSABI

[atgreen]

Commit fe203ff introduced these new failing tests:

FAIL: libffi.call/overread.c -W -Wall -Wno-psabi -O0 -DABI_NUM=FFI_GNUW64 -DABI_ATTR=MSABI execution test
FAIL: libffi.call/overread.c -W -Wall -Wno-psabi -O2 -DABI_NUM=FFI_GNUW64 -DABI_ATTR=MSABI execution test
FAIL: libffi.call/x32.c -W -Wall -Wno-psabi -O0 -DABI_NUM=FFI_GNUW64 -DABI_ATTR=MSABI execution test
FAIL: libffi.call/x32.c -W -Wall -Wno-psabi -O2 -DABI_NUM=FFI_GNUW64 -DABI_ATTR=MSABI execution test

@mikulas-patocka

[thesamesam]

This should be fixed with bb1a84e.