[Bug target/111107] i686-w64-mingw32 does not realign stack when __attribute__((aligned)) or __attribute__((vector_size)) are used

[zfigura at codeweavers dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111107

--- Comment #43 from Zeb Figura <zfigura at codeweavers dot com> ---
Right, sorry, I should clarify—I can see what the *actual* effect of
-mstackrealign / __force_align_arg_pointer__ is. I'm confused at what its
*intended* effect is. "Align to 16 bytes, but only if we need 16-byte
alignment, and do nothing if we need 8-byte alignment" seems very odd and not
intended.

If we have PREFERRED_STACK_BOUNDARY_DEFAULT set to 32 does -mstackrealign
actually ever do anything? IIUC it didn't do anything previously unless there
was something on *this* function's stack that needed alignment.
-mpreferred-stack-boundary seems to just be a stronger version of the same
flag.