dillon1000/react

Type inference across function expressions boundaries

Updates InferTypes to perform type inference across function boundaries. 
Specifically InferTypes is now responsible for driving type inference of 
function expressions (rather than deferring to AnalyzeFunctions to infer 
functions), and type inference now traverses into function expressions and 
infers types of free variables taking into account information from the outer 
context. This relies on the fact that identifier ids are consistent across 
function expression boundaries and that all free variables in functions are 
guaranteed to be effectively `const`, since we promote non-const variables used 
in function expressions to context variables.