AMDGPU: Fix v2f16 fneg/fabs pattern

The integer operation convertion for some reason only happens
if the source is a bitcast from an integer, which happens to
always be the situation when the result is loaded. Add
an additional pattern for when the source operation is really
an FP operation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333019 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed