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/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index 4bccc38..b1499c9 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -601,6 +601,8 @@
   case tok::kw_reinterpret_cast:
   case tok::kw_static_cast:
     return ParseCXXCasts();
+  case tok::kw_this:
+    return ParseCXXThis();
   case tok::at: {
     SourceLocation AtLoc = ConsumeToken();
     return ParseObjCAtExpression(AtLoc);