Added a comment about the launch_bounds attribute's AST node being required. Since there were no test cases for the attribute, some have been added. This promptly demonstrated a bug with the semantic handling, which is also fixed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197637 91177308-0d34-0410-b5e6-96231b3b80d8
[ms-abi] Update Alignment for VtorDisps

The alignment impact of the virtual bases apperas to be applied in 
order, rather than up front.  This patch adds the new behavior and 
provides a test case.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197639 91177308-0d34-0410-b5e6-96231b3b80d8