Currently, FIR reports errors caused by previous resolution failure. For
example with unresolved `a` and `b` in code `a.b`, both `a` and `b` are
highlighted. FE1.0 only highlights `a` since it's the root cause. This
change applies this heuristics when reporting FirDiagnostics.
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
Ivan Kochurkin