message: Fix the build of with bazel
  incompatible_merge_genfiles_directory enabled, which is enabled by default
  in bazel 0.24.
  Note that a build of //tensorflow/ops:math_ops_internal was not broken with the
  flag flip.
diff: @@ -42,15 +42,20 @@ namespace {
  const int kRightMargin = 79;
  // Converts:
  -// bazel-out/.../genfiles/(external/YYY/)?XX
  +// bazel-out/.../(bin|genfiles)/(external/YYY/)?XX
  // to: XX.
  string GetPath(const string& dot_h_fname) {
  - auto pos = dot_h_fname.find("/genfiles/");
  + auto pos = dot_h_fname.find("/bin/");
  string result = dot_h_fname;
  if (pos != string::npos) {
  // - 1 account for the terminating null character (\0) in "/genfiles/".
  + result = dot_h_fname.substr(pos + sizeof("/bin/") - 1);
  + } else {
  + pos = dot_h_fname.find("/genfiles/");
  + if (pos != string::npos) {
  result = dot_h_fname.substr(pos + sizeof("/genfiles/") - 1);
  }
  + }
  if (result.size() > sizeof("external/") &&
  result.compare(0, sizeof("external/") - 1, "external/") == 0) {
  result = result.substr(sizeof("external/") - 1);
  