- Don't pass 'verify' since it's now the default
- Update tests where diagnostics changed in a correct way to pass 'on' instead
- Delete compiler_scale/explicit_requirements_perf.swift since it's not testing anything with the requirement machine
This was only passing before because -requirement-machine-protocol-signatures=verify
only checked conformance requirements, and it would return the GSB's result if there
was a mismatch. It actually never did the right thing with the Requirement Machine.
Disable it until rdar://problem/88135912 is fixed.