Use atomic instructions on Bitrig armv6. Patch by Patrick Wildt.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@184113 91177308-0d34-0410-b5e6-96231b3b80d8
Cleanup linkage computation for static locals.

With this patch we assign VisibleNoLinkage to static locals in inline functions.
This lets us simplify CodeGen a bit.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@184114 91177308-0d34-0410-b5e6-96231b3b80d8