Fixes PR14801 - preprocessor directives shouldn't be indented

Uses indent 0 for macros for now and resets the indent state to the
level prior to the preprocessor directive.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171639 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/UnwrappedLineParser.h b/lib/Format/UnwrappedLineParser.h
index 69ac768..a8e5b73 100644
--- a/lib/Format/UnwrappedLineParser.h
+++ b/lib/Format/UnwrappedLineParser.h
@@ -124,6 +124,9 @@
   void nextToken();
   void readToken();
 
+  // FIXME: We are constantly running into bugs where Line.Level is incorrectly
+  // subtracted from beyond 0. Introduce a method to subtract from Line.Level
+  // and use that everywhere in the Parser.
   UnwrappedLine Line;
   FormatToken FormatTok;