message: fix(bazel): add this_is_bazel marker
  Add marker for noting that this check confirms we are running in a bazel environment.
  PR Close
diff: @@ -51,7 +51,7 @@ def _basename_of(ctx, file):
  # Return true if run with bazel (the open-sourced version of blaze), false if
  # run with blaze.
  def _is_bazel():
  - return not hasattr(native, "genmpm")
  + return not hasattr(native, "genmpm") # this_is_bazel
  def _flat_module_out_file(ctx):
  """Provide a default for the flat_module_out_file attribute.
  