[PATCH] [AArch64] Change default legalization behavior of v1i32 to be widen to v2i32 instead of scalarization

[Ahmed Bougacha]

I agree with Chandler, promotion isn't ideal, and from my quick experiments, it creates other problems by solving this one.
I guess we'll have to resort to working around the issue in the legalizer (Hao's solution #2, my #3, and the same as r205625).
See: http://reviews.llvm.org/differential/diff/15333/

Are you both fine with that?

(Also, I noticed a mistake in my comment: the problem is [[ http://llvm.org/bugs/show_bug.cgi?id=20777 | PR20777 ]], not 778.)

-Ahmed

http://reviews.llvm.org/D4322