Clean up ClassLinker::VerifyClass.

And drop kAccWasVerificationAttempted. It's not needed and duplicates
logic already present in the compiler and the class status.

This CL also enables nterp running methods with soft failures.

Test: test.py
Bug: 28313047
Change-Id: I853a6f00b9e0c38091d86fcd77167c92ff5b383c