resolve: Use NameBinding for local variables and generic parameters

[petrochenkov]

NameBinding is a structure used for representing any name introduction (an item, or import, or even a built-in).
Except that local variables and generic parameters weren't represented as NameBindings, for this reason they requires separate paths in name resolution code in several places.

This PR introduces NameBindings for local variables as well and simplifies all the code working with them leaving only the NameBinding paths.

[rust-highfive]

r? @estebank

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[cjgillot]

@bors r+

[bors]

📌 Commit e4e3c9a has been approved by cjgillot

[ehuss]

@bors r-

Failed in rollup #89992:

tidy error: /checkout/compiler/rustc_resolve/src/lib.rs: too many lines (3043) (add // ignore-tidy-filelength to the file to suppress this error)

[jyn514]

@bors rollup=iffy

[petrochenkov]

@bors r=cjgillot

[bors]

📌 Commit c1e8fc8 has been approved by cjgillot

[bors]

⌛ Testing commit c1e8fc8 with merge 4a2bec300777fb1a2450c5dd87f7b00792b99969...

[bors]

💥 Test timed out

[rust-log-analyzer]

A job failed! Check out the build log: (web)(plain)

Click to see the possible cause of the failure (guessed by this bot)

[petrochenkov]

@bors retry

[ehuss]

@bors retry

test-various hung after downloading the docker image, no clear reason.

[bors]

⌛ Testing commit c1e8fc8 with merge 6162529...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing 6162529 to master...

[rust-timer]

Finished benchmarking commit (6162529): comparison url.

Summary: This benchmark run did not return any relevant changes.

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

@rustbot label: -perf-regression

[rust-timer]

Finished benchmarking commit (6162529): comparison url.

Summary: ERROR categorizing benchmark run!

@rustbot label: -perf-regression

[rust-timer]

Finished benchmarking commit (6162529): comparison url.

Summary: This change led to very large relevant regressions 😿 in compiler performance.

• Very large regression in instruction counts (up to 99.5% on incr-unchanged builds of style-servo)

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression

[Mark-Simulacrum]

This'll need some manual checking locally to verify the regression given the potential environment changes to the collector, I'll try to do that.

[Mark-Simulacrum]

I'm pretty confident the regression is real. There's wall time regressions (including in e.g. self-profile results), so it seems to bear out in practice.

@petrochenkov I am inclined to revert this temporarily until there's a fix, unless the fix is simple and can be landed on the roughly same timeframe.

[petrochenkov]

Wow, not something that I'd expect.
I suggest reverting, I'll try to investigate this but not soon.

[Mark-Simulacrum]

Posted a revert #90130.