rename some MacroExpander-related ivars to TokenLexer.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@48073 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Lex/Directives.cpp b/Lex/Directives.cpp
index ea099f7..979c3c7 100644
--- a/Lex/Directives.cpp
+++ b/Lex/Directives.cpp
@@ -116,7 +116,7 @@
                                                 bool FoundNonSkipPortion,
                                                 bool FoundElse) {
   ++NumSkipped;
-  assert(CurMacroExpander == 0 && CurLexer &&
+  assert(CurTokenLexer == 0 && CurLexer &&
          "Lexing a macro, not a file?");
 
   CurLexer->pushConditionalLevel(IfTokenLoc, /*isSkipping*/false,