[Parser] Fix assertion-on-invalid for unexpected typename.

In `ParseDeclarationSpecifiers` for the code

    class A typename A;

we were able to annotate token `kw_typename` because it refers to
existing type. But later during processing token `annot_typename` we
failed to `SetTypeSpecType` and exited switch statement leaving
annotation token unconsumed. The code after the switch statement failed
because it didn't expect a special token.

The fix is not to assume that switch statement consumes all special
tokens and consume any token, not just non-special.

rdar://problem/37099386

Reviewers: rsmith, arphaman

Reviewed By: rsmith

Subscribers: jkorous-apple, cfe-commits

Differential Revision: https://reviews.llvm.org/D44449

llvm-svn: 329735

Author: vsapsai

clang/lib/Parse/ParseDecl.cpp

@@ -3804,7 +3804,8 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
 
     DS.SetRangeEnd(Tok.getLocation());
     if (DiagID != diag::err_bool_redeclaration)
-      ConsumeToken();
+      // After an error the next token can be an annotation token.
+      ConsumeAnyToken();
 
     AttrsLastTime = false;
   }

clang/test/Parser/cxx-decl.cpp

@@ -298,6 +298,11 @@ inline namespace ParensAroundFriend { // expected-error 0-1{{C++11}}
   }
 }
 
+namespace rdar37099386 {
+  class A typename A; // expected-error {{expected a qualified name after 'typename'}}
+  // expected-error@-1 {{cannot combine with previous 'class' declaration specifier}}
+}
+
 // PR8380
 extern ""      // expected-error {{unknown linkage language}}
 test6a { ;// expected-error {{C++ requires a type specifier for all declarations}}