Move name mangling support from CodeGen to AST.  In the
process, perform a number of refactorings:

- Move MiscNameMangler member functions to MangleContext
- Remove GlobalDecl dependency from MangleContext
- Make MangleContext abstract and move Itanium/Microsoft functionality
  to their own classes/files
- Implement ASTContext::createMangleContext and have CodeGen use it

No (intended) functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123386 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index 3574ba2..c7e0837 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -137,6 +137,8 @@
        E = OMD->param_end(); PI != E; ++PI)
     Args.push_back(std::make_pair(*PI, (*PI)->getType()));
 
+  CurGD = OMD;
+
   StartFunction(OMD, OMD->getResultType(), Fn, Args, OMD->getLocStart());
 }