Run semantics tests using the proper viaIR pipeline and make optimizer requirements explicit in the tests.

[ekpyron]

Basically we should do something along the lines of what #11949 tried.

[ekpyron]

Note that since the old PR, we're enabling minimal Yul optimizations by default, so this will change the setup. If we're lucky, none of the tests will require more optimization than the default minimal ones and we can get rid of the logic to re-run with the optimizer entirely (i.e. just run with default settings without --optimize and with optimizer when running with --optimize).
Conversely, the fact that we do have minimal optimizations by default now and the semantics tests use different settings makes addressing this more pressing.

There may be a complication with preserving the "homestead" test runs, since they are less resilient against stack issues. It's ugly, but if needed, we can preserve the "run twice" logic for those (no need to make that explicit in the tests, if it only applies to homestead), until we finally drop homestead support.