Separate out the AES-NI instructions from the SSE4.2 instructions. Add

Separate out the AES-NI instructions from the SSE4.2 instructions.  Add
a new subtarget option for AES and check for the support.  Add "westmere"
line of processors and add AES-NI support to the core i7.

Add a couple of TODOs for information I couldn't verify.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100231 91177308-0d34-0410-b5e6-96231b3b80d8