feat: implement shadowing rules

[petar-dambovaliev]

implements this

Most of the changes are fixing stdlib code where we get errors because of the new shadowing rules.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 47.49%. Comparing base (41ff374) to head (395bfd0).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1793      +/-   ##
==========================================
+ Coverage   44.80%   47.49%   +2.69%     
==========================================
  Files         459      388      -71     
  Lines       67651    61305    -6346     
==========================================
- Hits        30310    29117    -1193     
+ Misses      34801    29750    -5051     
+ Partials     2540     2438     -102     

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[deelawn]

Apart from my comment, I think it all looks good and makes sense so long as we're in agreement that this is want we want to do.

[kristovatlas]

Would it make sense to include tests for all Go built-in functions? I count about 19 of these currently listed here: https://go.dev/ref/spec#Built-in_functions

[kristovatlas]

I'm supportive of the concept for improved code security.

[deelawn]

Would it make sense to include tests for all Go built-in functions? I count about 19 of these currently listed here: https://go.dev/ref/spec#Built-in_functions

I think it's more than that -- probably everything grouped as a Predeclared Identifier on that page.

[petar-dambovaliev]

Would it make sense to include tests for all Go built-in functions? I count about 19 of these currently listed here: https://go.dev/ref/spec#Built-in_functions

done

[zivkovicmilos]

Looks good 💯

I'm not a fan of introducing even more panics into the codebase, but I realize there is no other option to stop execution currently (errors would require a much larger refactor)