FS conversion
FS conversion signatureHelp

three other change
New regression tests
Don't create a skipped token when encountering an extra comma while parsing an argument list.

Instead, synthesize a missing identifier so that we can accurately keep track of the number
of elements in the argument list.
Add keywords to completion list
rename findTokenOnLeft to findCompleteTokenOnLeft to be more precise
Formatting.
More regression tests
Updating keywords test to include more keywords in more locations
The display value for an object literal should use string literals if the literal was created that way.
Adding test.
Disable completion after dot in a numeric literal
Better error span for failed overload resolution
Fix accessibility checks.

We were using the receiver type to make the check, instead of the container type of
the member being checked.
Cleanup.
Some fixes to incremental edit and type check scenarios
More fixes to incremental edit and symbol update scenarios
Fix another incremental resolution bug
Fix error in parser error recovery.
Adding test.