default C++ operator new's alignment

[Andrea Pinski via Gcc]

What can we assume about the alignment about the default operator new
(the one without alignment supplied)?  Is it the same as malloc or
something different?
The reason why I am asking is right now a __builtin_assume_aligned is
not removed while with malloc it is. (https://gcc.gnu.org/PR127674).
Plus I assume we are losing some optimizations with respect to the
vectorizer we might peel for alignment in some cases where we don't
have to even try.

Thanks,
Andrea