[AArch64] Fix DAG selection for cmps for fp16 type

Summary: When emitting comparison for fp16, in addition to promote the LHS and RHS to fp32, we need to change the VT as well.

Reviewers: t.p.northover

Subscribers: t.p.northover, aemerson, rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D19922

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269151 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed