[GISEl]: Translate phi into G_PHI

G_PHI has the same semantics as PHI but also has types.
This lets us verify that the types in the G_PHI are consistent.
This also allows specifying legalization actions for G_PHIs.

https://reviews.llvm.org/D36990

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311596 91177308-0d34-0410-b5e6-96231b3b80d8
13 files changed