message: Suppress -Wself-assign in self-assignment tests, which triggers in newer clang revisions.
diff: @@ -321,7 +321,7 @@ TEST(FlatMap, Copy) {
  NumMap copy2;
  copy2 = src;
  EXPECT_EQ(Contents(src), Contents(copy2));
  - copy2 = copy2; // Self-assignment
  + copy2 = *&copy2; // Self-assignment, avoiding -Wself-assign.
  EXPECT_EQ(Contents(src), Contents(copy2));
  }
  }
  