[Bug c/79518] __builtin_assume_aligned should mark argument as aligned

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79518

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Why can't you use:
#define     __assume_aligned(arg, align)  arg = __builtin_assume_aligned (arg,
align)

?