Basic: Clean up malformed pragma diagnostics

Create a new diagnostic, -Wignored-pragmas and use it to handle any
case where a pragma would have a side effect but is ignored.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201102 91177308-0d34-0410-b5e6-96231b3b80d8
MS ABI: Add support for #pragma pointers_to_members

Introduce a notion of a 'current representation method' for
pointers-to-members.

When starting out, this is set to 'best case' (representation method is
chosen by examining the class, selecting the smallest representation
that would work given the class definition or lack thereof).

This pragma allows the translation unit to dictate exactly what
representation to use, similar to how the inheritance model keywords
operate.

N.B.  PCH support is forthcoming.

Differential Revision: http://llvm-reviews.chandlerc.com/D2723


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201105 91177308-0d34-0410-b5e6-96231b3b80d8
Tests for DR351-370, plus update DR status page to match the latest core issue list.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201106 91177308-0d34-0410-b5e6-96231b3b80d8