AsmParser: Reformat the MS asm parser to reduce nesting.

While there postpone register name printing after uniquing.
No intended functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175292 91177308-0d34-0410-b5e6-96231b3b80d8
add SCEVParameterRewriter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175293 91177308-0d34-0410-b5e6-96231b3b80d8
add ScevApplyRewriter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175294 91177308-0d34-0410-b5e6-96231b3b80d8