Update tests to solc v0.8.22 and fix a few tests

[seanyoung]

• Do not modify ns.diagnostics directly - ever. We may want to resolve an expression and drop all the diagnostics for it.
• Ensure all variable errors are surfaced
• Update solc testdata to v0.8.22

[codecov[bot]]

Codecov Report

Merging #1579 (89045f5) into main (979cad9) will increase coverage by 0.15%. Report is 1 commits behind head on main. The diff coverage is 100.00%.

:exclamation: Current head 89045f5 differs from pull request most recent head 4b55a80. Consider uploading reports for the commit 4b55a80 to get more accurate results

@@            Coverage Diff             @@
##             main    #1579      +/-   ##
==========================================
+ Coverage   87.40%   87.55%   +0.15%     
==========================================
  Files         133      133              
  Lines       64110    64118       +8     
==========================================
+ Hits        56033    56137     +104     
+ Misses       8077     7981      -96     

Files	Coverage Δ
src/abi/mod.rs	89.18% <100.00%> (+13.51%)	:arrow_up:
src/abi/polkadot.rs	97.75% <100.00%> (ø)
src/bin/solang.rs	68.29% <100.00%> (+0.88%)	:arrow_up:
src/sema/eval.rs	87.42% <100.00%> (+0.07%)	:arrow_up:
src/sema/expression/assign.rs	77.05% <100.00%> (ø)
src/sema/expression/literals.rs	89.91% <100.00%> (ø)
src/sema/expression/resolve_expression.rs	95.90% <100.00%> (ø)
src/sema/expression/subscript.rs	98.44% <100.00%> (ø)
src/sema/expression/variable.rs	91.05% <ø> (ø)
src/sema/functions.rs	93.14% <100.00%> (ø)
... and 3 more

... and 5 files with indirect coverage changes

[seanyoung]

I am not sure why the coverage bot is complaining. I get an overall failure but in all the files the coverage has gone up or stayed the same.

[LucasSte]

I am not sure why the coverage bot is complaining. I get an overall failure but in all the files the coverage has gone up or stayed the same.

In src/sema/tags.rs, lines 101-104 were previously covered by test, but are not covered anymore. Please, check the indirect changes in the coverage report.

[seanyoung]

In src/sema/tags.rs, lines 101-104 were previously covered by test, but are not covered anymore. Please, check the indirect changes in the coverage report.

Good point. I've added a bunch of test and now the coverage does not decrease (in fact, it increases).

There are some areas which are still uncovered, but I have not decided how to fix that. For example for the dot tests I think we need a solidity file with all the syntax in it (or just a minimal set of files). That's not in this PR.