Fix PR3938 by taking into account C99 6.10p4.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69413 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 502da73..be4da35 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -268,7 +268,7 @@
         // #else directive in a skipping conditional.  If not in some other
         // skipping conditional, and if #else hasn't already been seen, enter it
         // as a non-skipping conditional.
-        CheckEndOfDirective("else");
+        DiscardUntilEndOfDirective();  // C99 6.10p4.
         PPConditionalInfo &CondInfo = CurPPLexer->peekConditionalLevel();
         
         // If this is a #else with a #else before it, report the error.