fix rdar://7683173, rejecting an invalid conditional



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97253 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPExpressions.cpp b/lib/Lex/PPExpressions.cpp
index 2a6b2a7..3b620d0 100644
--- a/lib/Lex/PPExpressions.cpp
+++ b/lib/Lex/PPExpressions.cpp
@@ -106,7 +106,7 @@
 
   // Consume identifier.
   Result.setEnd(PeekTok.getLocation());
-  PP.LexNonComment(PeekTok);
+  PP.LexUnexpandedToken(PeekTok);
 
   // If we are in parens, ensure we have a trailing ).
   if (LParenLoc.isValid()) {