Before, the SwitchInt cases were computed in two passes: if the first
pass accepted e.g. 0..=5 and then 1, the second pass would not accept
0..=5 anymore because 1 would be listed in the SwitchInt options.

Now there's a single pass, so if we sort 0..=5 we must take care to not
sort a subsequent 1.

…on, r=matthewjasper

match lowering: don't collect test alternatives ahead of time

I'm very happy with this one. Before this, when sorting candidates into the possible test branches, we manually computed `usize` indices to determine in which branch each candidate goes. To make this work we had a first pass that collected the possible alternatives we'd have to deal with, and a second pass that actually sorts the candidates.

In this PR, I replace `usize` indices with a dedicated enum. This makes `sort_candidates` easier to follow, and we don't need the first pass anymore.

r? `@matthewjasper`

…iaskrgr

Rollup of 10 pull requests

Successful merges:

 - rust-lang#121820 (pattern analysis: Store field indices in `DeconstructedPat` to avoid virtual wildcards)
 - rust-lang#121908 (match lowering: don't collect test alternatives ahead of time)
 - rust-lang#122203 (Add `intrinsic_name` to get plain intrinsic name)
 - rust-lang#122226 (coverage: Remove or migrate all unstable values of `-Cinstrument-coverage`)
 - rust-lang#122255 (Use `min_exhaustive_patterns` in core & std)
 - rust-lang#122360 ( Don't Create `ParamCandidate` When Obligation Contains Errors )
 - rust-lang#122375 (CFI: Break tests into smaller files)
 - rust-lang#122383 (Enable PR tracking review assignment for rust-lang/rust)
 - rust-lang#122386 (Move `Once` implementations to `sys`)
 - rust-lang#122400 (Fix ICE in diagnostics for parenthesized type arguments)

r? `@ghost`
`@rustbot` modify labels: rollup

…iaskrgr

Rollup of 10 pull requests

Successful merges:

 - rust-lang#121820 (pattern analysis: Store field indices in `DeconstructedPat` to avoid virtual wildcards)
 - rust-lang#121908 (match lowering: don't collect test alternatives ahead of time)
 - rust-lang#122203 (Add `intrinsic_name` to get plain intrinsic name)
 - rust-lang#122226 (coverage: Remove or migrate all unstable values of `-Cinstrument-coverage`)
 - rust-lang#122255 (Use `min_exhaustive_patterns` in core & std)
 - rust-lang#122360 ( Don't Create `ParamCandidate` When Obligation Contains Errors )
 - rust-lang#122383 (Enable PR tracking review assignment for rust-lang/rust)
 - rust-lang#122386 (Move `Once` implementations to `sys`)
 - rust-lang#122400 (Fix ICE in diagnostics for parenthesized type arguments)
 - rust-lang#122410 (rustdoc: do not preload fonts when browsing locally)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#121908 - Nadrieril:dynamic-variant-collection, r=matthewjasper

match lowering: don't collect test alternatives ahead of time

I'm very happy with this one. Before this, when sorting candidates into the possible test branches, we manually computed `usize` indices to determine in which branch each candidate goes. To make this work we had a first pass that collected the possible alternatives we'd have to deal with, and a second pass that actually sorts the candidates.

In this PR, I replace `usize` indices with a dedicated enum. This makes `sort_candidates` easier to follow, and we don't need the first pass anymore.

r? ``@matthewjasper``