[perl #130249] Negative values are not allowed in --> part of the signature (sub f (--> -42) {})

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# New Ticket Created by  Aleks-Daniel Jakimenko-Aleksejev 
# Please include the string:  [perl #130249]
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# <URL: https://rt.perl.org/Ticket/Display.html?id=130249 >


Code:
sub foo (--> 42) {}
say foo

Result:
42

OK, that works, let's try -42:

Code:
sub foo (--> -42) {}
say foo

Result:
===SORRY!=== Error while compiling -e
Malformed return value
at -e:1
------> sub foo (-->⏏ -42) {}


｢- 42｣ is not a constant by itself, yes. But internally we provide a workaround 
for other places where a negative value may be needed (e.g. ｢sub foo(-42)｣, so 
I think this is where we should do it too.