Support my method syntax

[leonerd]

This came to light in discussions of Perl/PPCs#68 that my method doesn't actually parse as it should. This PR adds that.

Admittedly this syntax isn't all that useful without the corresponding ->&, so I'm happy to defer merging this until we can implement both at once. That way we'd avoid recommending to people the "just call it like a regular sub" workaround; as longterm we might not like that idea anyway.

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• This set of changes requires a perldelta entry, and it is included.

[esabol]

Nitpick: You have two sentences in a row which start with "This creates...." I suggest rephrasing one of them.

P.S. This is a great addition. Thanks, @leonerd.

[leonerd]

Ahyes; given it a slight edit.

[ivrntsv]

I guess it's a nitpicking, but nonetheless. Should it be state method? I suppose my method as my sub is redefind on each block execution. It doesn't matter in file scope executed once, but even in that case I prefer state sub version to not get bitten by habit in block scope (ofcourse not when I really need my sub as a closure, for example). Maybe there should be my and state methods. Or my method semantics is different from my sub and similar to state sub?

[haarg]

state sub and our sub already exist, so state method and our method should probably also exist.