Detect and handle COPY in many places.

This code is transitional, it will soon be possible to eliminate
isExtractSubreg, isInsertSubreg, and isMoveInstr in most places.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107547 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed