No longer accepting attribute spellings with prefix and suffix underscores except for GNU attributes, or C++11-style attributes in the GNU namespace. This prevents attributes such as __declspec(__dllexport__) or [[__noreturn__]] from being treated as known attributes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197082 91177308-0d34-0410-b5e6-96231b3b80d8
[ms-abi][cleanup] Removing FinalizeCXXLayout : no functional change

After r196549 there is no need to separate FinalizeCXXLayout and 
FinalizeLayout so they were merged and FinalizeCXXLayout was eliminated.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197083 91177308-0d34-0410-b5e6-96231b3b80d8