Implement Backref operand.
Implement IRRuntimeHelpers IS_DEFINED_CALL.
Fill out rest of RuntimeHelperCall logic.
Pass impl class into methods and clean up arg offset logic.
Implement BreakInstr.
Method bodies pass null for block type.
Implement ScopeModule.
Fix CompiledIRMethod construction for module/class bodies.
Gotta be able to do this some day. Don't bail out.
Implement RestArgMultipleAsgn instruction.
Use same function for ReqdArgMasgn in jit and interp.
Unnecessary cast.
Refactor arg-receiving instrs and reimpl JIT logic for them.
Eliminate unnecessary extra HashSet.
Recurse into closures and init temps there too.
Do not include entry BB in global rescue...init logic goes there.
Implement SetCapturedVar.
Implement InstanceSuper.
Fix signature for toplevel script entry point.
Fix handleNonLocalReturn signature.