We've muted some irText tests on JS in the previous commits because
test expectations in some tests are different when targeting JS.
AbstractKlibJsTextTestCase tests use a different logic:
they compare the dump of the deserialized IR with the frontend-generated
IR, not with the expectations in text files, thus muted tests weren't
actually failing.
Here we introduce a temporary fix, namely
a separate // IGNORE directive for klib tests.
When klib tests are moved to the new test infrastructure, there will be
no need to do this.
Sergej Jaskiewicz