clang-format: Improve handling of comments in binary expressions.

Before:
  b = a &&
      // Comment
      b.c &&
      d;

After:
  b = a &&
      // Comment
      b.c && d;

This fixes llvm.org/PR21535.

llvm-svn: 221727
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 715cbf0..8ec8f58 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -1149,8 +1149,7 @@
           Current->OperatorIndex = OperatorIndex;
           ++OperatorIndex;
         }
-
-        next(/*SkipPastLeadingComments=*/false);
+        next(/*SkipPastLeadingComments=*/Precedence > 0);
       }
     }
   }