Sema: resolve elem type for non-default aligned ptrs

Before this commit, I observe a crash from this abiSize call because the
element type is a struct that is not yet resolved. This is triggered by
running the behavior tests with -ofmt=c -target x86_64-windows.
36da3000c0Andrew Kelley committed on 12/6/2022, 7:54:58 AMparent80be5e4
1 file changedLine totals unavailable