Move code out of the compiler state into the language service.
Move host synchronization into the compiler state object.
Rename fields.
Don't pass a settings object to the reference resolver when all it needs is a single setting property.
Rename CompilerState to LanguageServiceCompiler.
Move caching of the current edited syntax tree to its own class.
No need to store data about which function parameter we're in.  We can determine this syntactically.
Use foreach in a few places.
Remove unused code.
Accessors can't be signatures.  Removing unnecessary code.
Massage code for processing accessors.
Remove methods and use flags.
Provide specialized nodes for get/set property assignments.
As a decl for it's symbol, not the binder.
Simplifying object literal resolution code.
Bring the syntax nodes for accessor properties more in line with those for accessor members.
remove unnecessary code.
Provide specialized nodes for accessors.
Remove unused flag.
Introduce a specialized node for function expressions.