stage2: update vector alignment logic

This follows LLVM14's lead on vector alignment, which computes byte
count based on the length premultiplied by bits.

This commit also disables behavior tests regressed by LLVM 14, only for
stage1. stage2 fortunately does not trip the regression.
b698168664Andrew Kelley committed on 7/3/2022, 8:33:09 PMparent15f111a
2 files changedLine totals unavailable