Added "InitializeTU" to ASTConsumer. This is used by Sema::ParseAST to pass a
TranslationUnit object instead of an ASTContext. By default it calls
Initialize(ASTConstext& Context) (to match with the current interface used by
most ASTConsumers).

Modified the ObjC-Rewriter to use InitializeTU, and to tell the TranslationUnit
to not free its Decls.  This is a workaround for: <rdar://problem/5966749>


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@51825 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/ParseAST.cpp b/lib/Sema/ParseAST.cpp
index cff3ef7..9199179 100644
--- a/lib/Sema/ParseAST.cpp
+++ b/lib/Sema/ParseAST.cpp
@@ -46,7 +46,7 @@
   // Initialize the parser.
   P.Initialize();
   
-  Consumer->Initialize(Context);
+  Consumer->InitializeTU(TU);
   
   Parser::DeclTy *ADecl;