fix: report a range for illegal stable patterns

[christoph-dfinity]

Does so by annotating the default stability with the range of the full declaration in the parser.

[christoph-dfinity]

Wow this is cursed. The current warnings for "implicit transient" rely on the parser desugared Flexible annotations on functions being non-no-region, and the parser desugared Stable on let and var being no-region.

I'll come back to this at some point. Making it a draft for now.

[github-actions]

Comparing from 5df40b5 to a25b71e:
The produced WebAssembly code seems to be completely unchanged.
In terms of gas, no changes are observed in 5 tests.
In terms of size, no changes are observed in 5 tests.

[crusso]

Wow this is cursed. The current warnings for "implicit transient" rely on the parser desugared Flexible annotations on functions being non-no-region, and the parser desugared Stable on let and var being no-region.

I'll come back to this at some point. Making it a draft for now.

Right, I was about to say we rely on no_region to tell it was default. I guess one could add a bool somewhere...

[christoph-dfinity]

Right, I was about to say we rely on no_region to tell it was default. I guess one could add a bool somewhere...

This'll go away when we properly remove transient by default actors, right? I'd rather wait for/do that.