By convention, compiletest directives starting with `ignore-*` normally cause
the test itself to be skipped under certain conditions.
The `//@ ignore-pass` directive was the only exception to that convention. The
new name should hopefully do a better job of communicating its effect, which is
to cause the `--pass` flag to not override the test's `build-pass` or
`run-pass` directive.
The `//@ no-pass-override` directive is mainly useful for tests that expect
warnings produced during codegen.