Fix type of LUXC1 and SUXC1. These instructions were incorrectly defined as

Fix type of LUXC1 and SUXC1. These instructions were incorrectly defined as
single-precision load and store.

Also avoid selecting LUXC1 and SUXC1 instructions during isel. It is incorrect
to map unaligned floating point load/store nodes to these instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161063 91177308-0d34-0410-b5e6-96231b3b80d8