Fixes for functions (#471)

* call super().__init__() in mappers

* fixes for functions

* add update_from_callee_clone function to update parent mapper's side effect data

* fix _DistributedInputReplacer

* failed attempt at tweaking MPMSMaterializer to avoid type checking issue

if rec is supposed to call map_call, map_call should return an MPMSMaterializer

* remove implementation of DirectPredecessorsGetter.map_named_call_result

* back out some placeholder stuff

* remove implementation of LocalSendRecvDepGatherer.map_named_call_result

* fix arg checking in FunctionDefinition.__call__

* forget about functions in MPMSMaterializer for now

* handle results from non-inlined calls correctly in Inliner

* remove update_from_callee_clone

* move CodeGenPreprocessor function error to map_named_call_result

* remove unused mypy ignore