[foreach] Deprecate ref for array index or ForeachRangeStatement

[ntrel]

Fix Bugzilla 24499 - foreach over a ref parameter to an rvalue should be an error
Fix Bugzilla 24232 - ref for index of foreach for arrays is not allowed by spec but accepted by compiler

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	24232	normal	ref for index of foreach for arrays is not allowed by spec but accepted by compiler.
✓	24499	normal	foreach over a ref parameter to an rvalue should be an error

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#16381"

[ntrel]

Fix Bugzilla 24232

For some reason that didn't get picked up by dlang-bot.

Edit: added a separate commit saying that, now it got picked up. Does it not find multiple issues?

[dkorpel]

Does it not find multiple issues?

I think it does when you list them like "Fix Bugzilla 24499, 24232"