Remove optional static registration for hlo dialects again.

Instead, we invoke multiple test tools in a row in end to end tests now. For hlo dialects and passes, we use mlir-hlo-opt explicitly.

PiperOrigin-RevId: 324989884

lib/Dialect/mhlo/transforms/register_all_passes.cc

@@ -1,28 +0,0 @@
-/* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-==============================================================================*/
-
-#include "mlir-hlo/Dialect/mhlo/transforms/register_passes.h"
-
-namespace mlir {
-
-namespace {
-
-bool register_all_passes = ([] {
-    mhlo::registerAllMhloPasses();
-  lmhlo::registerAllLmhloPasses();
-}(), true);
-
-}  // namespace
-}  // namespace mlir