Removing a signed/unsigned mismatch warning triggered in MSVC 11.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@174986 91177308-0d34-0410-b5e6-96231b3b80d8
[ms-inline asm] Add a few test cases for the parsing of hexidecimal integers.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@174989 91177308-0d34-0410-b5e6-96231b3b80d8