Rename DeclContext::getLookupContext to getRedeclContext and change its semantics slightly. No functionality change in the absence of inline namespaces. Also, change a few places where inline namespaces actually make a difference to be prepared for them.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112563 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 97ee76c..6183154 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -347,7 +347,7 @@
                                         const FunctionDecl *Fn) {
   // Must be in global scope.  Note that allocation functions can't be
   // declared in namespaces.
-  if (!Fn->getDeclContext()->getLookupContext()->isFileContext())
+  if (!Fn->getDeclContext()->getRedeclContext()->isFileContext())
     return false;
 
   // Signature must be void *operator new[](size_t, void*).