Regenerate tests
Simplify codegen for trait methods with implementations

Use existing framework (FunctionCodegen.generateMethod) which will take care of
all subtleties of method generation (bridges, annotations, thrown exceptions,
etc).

Call to "generateThisOrOuter" was not needed, since when we're generating
delegation to TImpl, "this" is always "ALOAD 0"
Minor, move and rename getExceptions

Should only be used in FunctionCodegen from now on, because every method
generation should go through FunctionCodegen
Simplify bridges algorithm in codegen

- fix a typo (which apparently didn't matter)
- queue now always contains originals, no need to invoke getOriginal()
- no need to add current descriptor's original anymore, this was a hack working
  around a problem with trait-impl which was fixed by another change
- a small optimization: don't do anything for constructors