Enable reserved_stack argument to Threads.@spawn

[MilesCranmer]

Fixes #55200. The mechanism is to simply forward whatever is passed to a reserved_stack keyword to the reserved_stack argument in Task. By default this is 0, so that is also the macro default.

Usage:

Threads.@spawn reserved_stack=(8 * 1024 * 1024) sleep(100)
# => Task(() -> sleep(100), 8 * 1024 * 1024)

It is compatible with the threadpool argument, and the order is arbitrary:

stack_size = 4 * 1024^2
Threads.@spawn :interactive reserved_stack=stack_size sleep(100)
Threads.@spawn reserved_stack=stack_size :interactive sleep(100)

x-ref #55200 #55185 #55184 #54998

[MilesCranmer]

@ararslan both have been added

[vchuravy]

I am not a fan of mixing both keyword argument and positional style in macros.
It makes them quite a bit harder to read. I would make the order required with threadpool; kwargs... like a normal function call.

I wonder if we could factor out the logic of parsing the kwargs to the macro.
It looks similar to gen_call_with_extracted_types_and_kwargs

[MilesCranmer]

I wonder if we could factor out the logic of parsing the kwargs to the macro. It looks similar to gen_call_with_extracted_types_and_kwargs

I was meaning to ask about this. Is there was a standard way to handle kwargs in Julia macros that live in Base?