PR #83567 ports `SelectionDAGISel` to the new pass manager, then each
backend should provide `<Target>DagToDagISel()` in new pass manager
style. Then each target should provide `<Target>PassRegistry.def` to
register backend passes in `registerPassBuilderCallbacks` to reduce
duplicate code.
This PR adds `AArch64PassRegistry.def` to AArch64 backend and
boilerplate code in `registerPassBuilderCallbacks`.
29bf32efbb