[PATCH] Fix assertion with a trunc store to an i1 vector.

[Quentin Colombet]

IIRC the semantic of Y x i1 is a packed vector of bool. I.e., you just need Y bits to hold the whole vector. This matches the AVX-512 vector mask.
That said, I do not find the thread discussing that and may be wrong.

Adding Nadav and Hal may be a good idea.

-Quentin

http://reviews.llvm.org/D3163