dillon1000/react

POC of new expression-oriented inference model for memoization within control-flow (#589)

* [hir] Core data types and lowering for new model

* Handle more expressions, including using babel for binding resolution

* test setup with pretty printing of ir

* Basic codegen and improved pretty printing

* avoid else block when if has no fallthrough

* emit function declarations with mapped name/params

* start of scope analysis

* saving state pre-run

* add slightly more complex example and flush out lowering/printing (jsx, new, variables)

* Various improvements:
* Convert logical expressions (|| and &&) to control flow, accounting
  for lazy evaluation semantics.
* Handle expression statements
* Improve printing of HIR for unsupported node kinds
* Handle more cases of JSX by falling by to OtherStatement to wrap
  subtrees at coarse granularity.

* improve HIR printing, lowering of expression statements

* handle object expression printing

* improve IR model for values/places along w codegen

* more test cases

* start of mutability inference

* passable but still incorrect mutability inference

* improved mutability inference, should cover most cases now

* visualization of reference graph

* correctly flow mutability backwards (have to actually set the capability)

* separate visualization in output

* consolidate on frozen/readonly/mutable capabilities

* cleanup

* conditional reassignment test (not quite working)

* hack to output svg files for debugging

* handle conditional reassignment

* improve capture analysis

* treat jsx as (interior) mutable; handle memberexpression lvalues

* lots of comments; hook return is frozen

* update main comment

* inference for switch, which reveals a bug

* fix yarn.lock