Stabilize const_float_classify

[eduardosm]

Tracking issue: #72505

Also reverts #114486

Closes #72505

Stabilized const API:

impl f32 {
    pub const fn is_nan(self) -> bool;
    pub const fn is_infinite(self) -> bool;
    pub const fn is_finite(self) -> bool;
    pub const fn is_subnormal(self) -> bool;
    pub const fn is_normal(self) -> bool;
    pub const fn classify(self) -> FpCategory;
    pub const fn is_sign_positive(self) -> bool;
    pub const fn is_sign_negative(self) -> bool;
}

impl f64 {
    pub const fn is_nan(self) -> bool;
    pub const fn is_infinite(self) -> bool;
    pub const fn is_finite(self) -> bool;
    pub const fn is_subnormal(self) -> bool;
    pub const fn is_normal(self) -> bool;
    pub const fn classify(self) -> FpCategory;
    pub const fn is_sign_positive(self) -> bool;
    pub const fn is_sign_negative(self) -> bool;
}

cc @rust-lang/wg-const-eval @rust-lang/libs-api

[rustbot]

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[bors]

☔ The latest upstream changes (presumably #130253) made this pull request unmergeable. Please resolve the merge conflicts.

[thomcc]

I think libs-api needs to handle these?
r? libs-api

[RalfJung]

Cc @rust-lang/wg-const-eval -- this is entirely harmless, the methods just all use already-stable const facilities.

(Team pings only work when an org member writes them, AFAIK.)

[tgross35]

Also reverts #114486

Nit: could you put this PR link and/or the relevant commit SHAs in that commit message? It's currently just a title so no crosslinking.

[RalfJung]

The PR link is in the PR description which bors will put into the merge commit message. So I think that will be covered.

[RalfJung]

FCP passed, so this is good to go. :)

@bors r+

[bors]

📌 Commit c39ae56 has been approved by RalfJung

It is now in the queue for this repository.

[bors]

⌛ Testing commit c39ae56 with merge 14f303b...

[bors]

☀️ Test successful - checks-actions
Approved by: RalfJung
Pushing 14f303b to master...

[rust-timer]

Finished benchmarking commit (14f303b): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (secondary -0.8%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.8%	[-0.8%, -0.8%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary 2.9%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.9%	[2.9%, 2.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 771.465s -> 771.36s (-0.01%)
Artifact size: 342.03 MiB -> 342.03 MiB (-0.00%)