test: migrate math/base/special/rempio2f to ULP-based testing

[Planeshifter]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates test/test.js and test/test.native.js for math/base/special/rempio2f from relative-tolerance (EPS-based) assertions to ULP-difference assertions using @stdlib/number/float32/base/assert/is-almost-same-value (single-precision variant, following the convention used for other f packages such as acothf and atanhf), with the minimum required ULP values.
• removes the now-unused absf and EPS requires and the delta/tol variables from migrated test blocks.

Details on the chosen ULP values:

• This package has no fixtures; all five tolerance blocks are property-based round-trip checks comparing z = float64ToFloat32( (PIO2*n) + y[0] ) against the input x, with unseeded randu inputs in three of the blocks. Because the per-run ULP difference is not deterministic for random inputs, the bound was certified by exhaustive enumeration of all 1,120,403,456 single-precision values in (0, 100] for each sign: the maximum ULP difference is 1 in both directions, and roughly 0.35% of inputs in the domain produce a 1-ULP difference, so a 0 ULP tolerance would flake. 1 is therefore the minimum ULP value which never fails. The deterministic multiples-of-π/4 block likewise has a maximum ULP difference of 1 (2 of 20 cases are not exact).
• The two "tiny" blocks degenerate: float64ToFloat32( ±1.0e-100 * randu() ) underflows to ±0, so the reconstruction is exact and the assertions use plain t.strictEqual( z, x, ... ) per the migration guidelines for exactly matching values.
• The native (C) implementation was verified via a dense sweep (2e7 points per sign plus the π/4 set) to have the same maximum ULP difference of 1, with the tiny blocks exact, so the native ULP values are identical to the JavaScript values and no divergence note is required.

The minimum ULP values were independently re-verified by direct ULP-difference computation (exhaustive single-precision domain enumeration) prior to opening this pull request.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

No.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

This PR was written by Claude Code as part of an automated migration of test suites to ULP-based assertions (issue #11352). The minimum ULP values were computed programmatically and independently verified by a second adversarial agent before opening this PR.

---

@stdlib-js/reviewers

[stdlib-bot]

Hello! 👋

We've noticed that you've been opening a number of PRs addressing good first issues. Thank you for your interest and enthusiasm!

Now that you've made a few contributions, we suggest no longer working on good first issues. Instead, we encourage you to prioritize cleaning up any PRs which have yet to be merged and then proceed to work on more involved tasks.

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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/rempio2f	$\\color{red}632/645$ $\\color{green}+97.98\\%$	$\\color{red}45/50$ $\\color{green}+90.00\\%$	$\\color{green}4/4$ $\\color{green}+100.00\\%$	$\\color{red}632/645$ $\\color{green}+97.98\\%$

The above coverage report was generated for the changes in this PR.