When a call is resolved to a classifier, only a single error message was
being used for multiple cases. This lead to confusion as the default
message may not be applicable to a given error case. Added additional
errors and messages to distinguish between these error cases.
#KT-57251 Fixed
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.
Brian Norman