fix: Replace Just the variable name in Unused Variable Diagnostic Fix
Changes Unused Variable diagnostic to just look at the variable name, not the entire syntax range.
Also added a test for an unused variable in an array destructure.
Closes#17053
internal: Enforce utf8 paths
Cargo already requires this, and I highly doubt r-a works with non-utf8 paths generally either. This just makes dealing with paths a lot easier.
Add fuel to match checking
Exhaustiveness checking is NP-hard hence can take extremely long to check some specific matches. This PR makes ehxaustiveness bail after a set number of steps. I chose a bound that takes ~100ms on my machine, which should be more than enough for normal matches.
I'd like someone with less recent hardware to run the test to see if that limit is low enough for them. Also curious if the r-a team thinks this is a good ballpark or if we should go lower/higher. I don't have much data on how complex real-life matches get, but we can definitely go lower than `500 000` steps.
The second commit is a drive-by soundness fix which doesn't matter much today but will matter once `min_exhaustive_patterns` is stabilized.
Fixes https://github.com/rust-lang/rust-analyzer/issues/9528 cc `@matklad`
fix: Ignore some warnings if they originate from within macro expansions
These tend to be annoying noise as we can't handle `allow`s for them properly for the time being.
internal: Compute syntax validation errors on demand
The LRU cache causes us to re-parse trees quite often, yet we don't use the validation errors at all. With this we push calculating them off to the caller who is interested in them.
fix: Don't panic on synthetic syntax in inference diagnostics
Temporary fix for https://github.com/rust-lang/rust-analyzer/issues/16682
We ought to rethink how we attach diagnostics to things, as IDs don't work for `format_args` like that!
