There was a refactoring of AbstractDiagnosticsTest in 9052ef06 which
contains bug that `setupEnvironment` for AbstractDiagnosticsTestUsingJavac
was not called, so for last year tests `UsingJavac` had no difference
with usual diagnostics tests which causes some contradictions in test data
Enable check for error supertypes during CST calculation in classic type system context.
Cyclic upper bound + known type parameters of superclasses may create non-error types
with error supertypes. Such types don't have common constructors with other normal types
and cause assertion errors during intersection.
^KT-36951 Fixed
Victor Petukhov