[x86] clean up code for converting 16-bit ops to LEA; NFC

As discussed in D55494, we want to extend this to handle 8-bit
ops too, but that could be extended further to enable this on
32-bit systems too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348851 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed