[Bug testsuite/108427] bitfield tests fail with missing warnings

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108427

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
-mms-bitfields is enabled by default.

See TARGET_MS_BITFIELD_LAYOUT_P and
https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gcc/x86-Options.html#index-mms-bitfields

The layout of bitfields are different here ...