Many refinements to Sema::MergeVarDecl(). This routine still needs some re-work to fully handle tentative decls.

This includes a fix to bz1908.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@46540 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed