stage2: Ensure f128 alignment matches c_longdouble alignment

On platforms where c_longdouble is 128-bits, interop with C code
is simplified by making f128 match the alignment of c_longdouble.

I intended to make this change as part of #13257, but I missed this
part.
3ee5cf627fCody Tapscott committed on 11/2/2022, 9:11:40 PM· committed by Andrew Kelleyparenta0ac10d
1 file changedLine totals unavailable