Remove Passes dependency on CodeGen

Remove Passes dependency on CodeGen

The dependency was introduced in
5134020ea62d1e1e125fdac48d251a26b80e9781. The only functional change
from this removal would be the new PM interface for the two codegen
passes. This is not necessary since we don't have codegen pipeline using
new PM yet. This removal is to break the potential circular dependency between
Passes and CodeGen once the codegen begins to gain new PM support.