One last RandomAccessIterator operator for PreprocessingRecord::iterator

llvm-svn: 135680

clang/include/clang/Lex/PreprocessingRecord.h

@@ -419,6 +419,11 @@ namespace clang {
       friend difference_type operator-(const iterator &X, const iterator &Y) {
         return X.Position - Y.Position;
       }
+
+      friend iterator operator-(iterator X, difference_type D) {
+        X.Position -= D;
+        return X;
+      }
     };
     friend class iterator;