To do so, inside the root cause of inapplicable candidate errors,
we will record expected/actual type of receiver, if any.
That will help identifying inapplicable calls on nullable receiver.
This commit introduces several different things, in particular:
- check type arguments in expressions
- new TypeArgumentList node to deal with diagnostic source
- ConeDiagnostic was moved to fir:cones
- ConeIntermediateDiagnostic to use in inference (?) without reporting
- detailed diagnostics on error type
Mikhail Glukhikh