Add parsing support for C++ classes.

Note that Parser::ParseCXXMemberSpecification is temporarily disabled until the Sema support is in place.
Once ParseCXXMemberSpecification is enabled, the Parser/cxx-class.cpp test will pass.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@52694 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 51223a7..8ff7e9f 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -23,6 +23,8 @@
   NumCachedScopes = 0;
   ParenCount = BracketCount = BraceCount = 0;
   ObjCImpDecl = 0;
+  // Instantiate a LexedMethodsForTopClass for all the non-nested classes.
+  PushTopClassStack();
 }
 
 ///  Out-of-line virtual destructor to provide home for Action class.