Some minor cleanups:

Some minor cleanups:
1. Compute action in X86SelectSelect based on MVT instead of type.
2. Use TLI.getValueType(..) instead of MVT::getVT(..) because the former
   handles pointers and the later doesn't.
3. Don't pass TLI into isTypeLegal, since it already has access to it as
   an ivar.

#2 gives fast isel some minor new functionality: handling load/stores of
pointers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57552 91177308-0d34-0410-b5e6-96231b3b80d8