[ARM] Remove target-specific ITOFP/FPTOI nodes

Anton tried this 5 years ago but it was reverted due to extra VMOVs
being emitted. This can be easily fixed with a liberal application
of patterns - matching loads/stores and extractelts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232958 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed