Fix assertion failure in PTH when tokens followed a closing #endif.

- Ted, please check.

 - Missing test case because PTH won't reliably cache the tokens in a
   test case. *cough*

llvm-svn: 68966

clang/lib/Lex/PPDirectives.cpp

@@ -351,10 +351,9 @@ void Preprocessor::PTHSkipExcludedConditionalBlock() {
       if (!CondInfo.FoundNonSkip) {
         CondInfo.FoundNonSkip = true;
         
-        // Consume the eom token.
+        // Scan until the eom token.
         CurPTHLexer->ParsingPreprocessorDirective = true;
-        LexUnexpandedToken(Tok);
-        assert(Tok.is(tok::eom));
+        DiscardUntilEndOfDirective();
         CurPTHLexer->ParsingPreprocessorDirective = false;
         
         break;