[Bug target/66697] Feature request: -mstackrealign and force_align_arg_pointer for x86_64

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66697

--- Comment #22 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Justas L from comment #21)
> When is MIN_STACK_BOUNDARY equal to 128? I thought it defaulted to 64 (8*8)
> for x86_64 and 32 (4*8) for x86, no?

i386.h has

* Minimum stack boundary.  */
#define MIN_STACK_BOUNDARY (TARGET_64BIT ? (TARGET_SSE ? 128 : 64) : 32)