Fix spurious remarks when -Weverything is used.

With -Weverything, the backend remarks are enabled. This was
causing spurious diagnostics for remarks that we don't yet
handle (cf http://reviews.llvm.org/D3683).

This will stop being a problem once http://reviews.llvm.org/D3683
is committed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209823 91177308-0d34-0410-b5e6-96231b3b80d8
No longer allow the -std options to entirely override the -x language option. This allows -x cuda -std=c++11, for instance.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209824 91177308-0d34-0410-b5e6-96231b3b80d8
Sema: Check dll attributes on static data members

Redeclarations cannot add a dll attribute and static data members cannot
be defined.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209825 91177308-0d34-0410-b5e6-96231b3b80d8
MS ABI: Emit static data members with proper linkage

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209826 91177308-0d34-0410-b5e6-96231b3b80d8
Sema: Functions with dll attributes cannot be deleted

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209827 91177308-0d34-0410-b5e6-96231b3b80d8
Add missing -S to avoid invoking assembler unnecessarily.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209828 91177308-0d34-0410-b5e6-96231b3b80d8