This ensures correct generation of generic signatures in the resulting
byte code, but it _is_ a work in progress: the actual type *arguments*
passed for these parameters during compilation are dummy `Any?` types.
Sites that need more work are indicated with TODO's.
- copy type parameters of interfaces to methods moved to DefaultImpls
- implement type parameter renaming scheme from JVM, with proper
renaming and substitution.
- adjust call sites in bridges in classes->DefaultImpls
- adjust call sites in bridges from DefaultImpls->Interface
- adjust call sites in bridges from DefaultImpls->DefaultImpls
- adjust super calls ->DefaultImpls
- adjust calls in code of Interfaces->DefaultImpls
Kristoffer Andersen