Add support for registering pass pipelines to the PassRegistry. This is done...

Add support for registering pass pipelines to the PassRegistry. This is done by providing a static registration facility PassPipelineRegistration that works similarly to PassRegistration except for it also takes a function that will add necessary passes to a provided PassManager.

  void pipelineBuilder(PassManager &pm) {
      pm.addPass(new MyPass());
      pm.addPass(new MyOtherPass());
  }

  static PassPipelineRegistration Unused("unused", "Unused pass", pipelineBuilder);

This is also useful for registering specializations of existing passes:

  Pass *createFooPass10() { return new FooPass(10); }

  static PassPipelineRegistration Unused("unused", "Unused pass", createFooPass10);

PiperOrigin-RevId: 235996282