Throwing initializers don't support `throw` code inline

[bradcray]

In working on #26430 I found that initializers that throw can do so by calling a procedure that throws, but not by using throw statements themselves directly (or at least, the ones I tried). Support for throwing initializers is a WIP and it may be that this is a known limitation of the current implementation, but I couldn't find a mention of it in the technote about throwing initializers, so wanted to capture the issue here.

It seems as though the implementation of this could be fairly straightforward:

• check whether the initializer throws
• if it does, outline all code following the init this; into a nested procedure that throws, replacing it with a call to that procedure

test/classes/initializers/errors/errHandling/throwWithoutHelper.chpl #26430

[bradcray]

Note that it may make sense to get this right in dyno rather than fixing it in the production compiler, at least if it isn't needed by users / us before then.

[lydia-duncan]

I couldn't find a mention of it in the technote about throwing initializers

It's in the future work section of the technote