What is the expected behavior?

This is part of cleaning up the transpiler. Currently we have preserved backwards compatibility by following the old code path of circuit transformations when no pass manager is used in compile(). That old path is a bunch of hardcoded transformations. To fully complete the transition to the transpiler architecture, we need to remove that old path, and create a default pipeline of passes that gets used when pass_manager=None.

Note that a PR that closes this issue must also close #157.