In K1, upper bound violated causes candidate to have lower applicability
due to constraint errors, in K2 however constraint errors has to be
reported explicitly
This directive anyway does not make test run twice with OI, and with NI
It only once run the test with specific settings (// LANGUAGE)
and ignores irrelevant (OI or NI tags)
Previously unsafe call is reported as part of InapplicableWrongReceiver.
This makes it difficult for the downstream checkers to report different
diagnostics.
Nikolay Lunyak