This separates the different parts of compiler.cpp to make their relationship more clear. In particular it adds:

• sugared_value.{h,cpp} - all the public SugaredValues that the compiler defines and a few that were inside compiler.cpp
• type_parser.{h, cpp} - Turns TreeRef's defining types into TypePtr
• schema_matching.{h, cpp} - infrastructure for matching arguments against overloaded schema and emitting builtin operators with a particular schema.
  Retains:
• compiler.{h, cpp} - now responsible simply for the defineMethodsInModule infra structure.

Some utility functions like inlineCallTo have moved to ir.h.

Only thing that is not a move is some changes in module.h/cpp that remove multiple returns from Method::emit_call_to.