Add more tests to t/run/todo.t

[khwilliamson]

• This set of changes does not require a perldelta entry.

[jkeenan]

Test failed CI; please see https://github.com/Perl/perl5/pull/22680/checks

[jkeenan]

I checked out this branch, rebased on blead, built and tested. I got this result.

$ cd t;./perl harness -v run/todo.t; cd -

ok 1 - GH \#16894
not ok 2 - "abcde5678" =~ / b (*pla:.*(*plb:(*plb:(.{4}))? (.... # TODO GH 16250
ok 3 - No assertion failure # TODO GH 16876
ok 4 - No assertion failure # TODO GH 16952
not ok 5 - No assertion failure # TODO GH 16971
ok 6 - No assertion failure # TODO GH 16627
ok
All tests successful.

Test Summary Report
-------------------
run/todo.t (Wstat: 0 Tests: 6 Failed: 0)
  TODO passed:   3-4, 6
Files=1, Tests=6,  0 wallclock secs ( 0.00 usr  0.00 sys +  0.02 cusr  0.01 csys =  0.03 CPU)
Result: PASS

Is there a better place to put tests that were once TODOed but are now passing?

[khwilliamson]

There may be a better place, but I left it here to show that it could be left here.

[tonycoz]

Don't these belong in the test scripts that test that particular op? like the many other TODO tests?

[khwilliamson]

Yes, but my goal here was to make it easier for someone to just start going through tickets and copying the tests without having to think about anything more than necessary. They can be moved later.