test: migrate math/base/special/cceiln to ULP-based assertions

[Planeshifter]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates math/base/special/cceiln test cases from relative tolerance testing (EPS * abs(...)) to ULP difference testing using @stdlib/assert/is-almost-same-value.
• updates both test/test.js and test/test.native.js, which shared the same tolerance-based assertion block (subnormal rounding test case).
• uses a single named ULP constant (value 1), determined to be the minimum ULP bound that still passes the full fixture set. A tolerance of 0 (exact equality) fails 8 of the added assertions, confirming 1 is the tightest bound.

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.

Measured minimum ULP bound: 1 (verified by lowering from 64; 0 fails, 1 passes deterministically across two consecutive runs of the full suite).

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

If you answered "yes" to using AI assistance, please provide a short disclosure indicating how you used AI assistance. This helps reviewers determine how much scrutiny to apply when reviewing your contribution. Example disclosures: "This PR was written primarily by Claude Code." or "I consulted ChatGPT to understand the codebase, but the proposed changes were fully authored manually by myself.".

This PR was authored by Claude Code, run as an unattended scheduled task on my account. It studied issue #11352 and several already-merged conversion commits (e.g. math/base/special/csignum, math/base/special/asindf) to mirror the established idiom, then converted the tolerance-based assertions in this package to isAlmostSameValue calls and empirically determined the minimum passing ULP bound.

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@stdlib-js/reviewers

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Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/cceiln	$\\color{green}188/188$ $\\color{green}+0.00\\%$	$\\color{green}5/5$ $\\color{green}+0.00\\%$	$\\color{green}2/2$ $\\color{green}+0.00\\%$	$\\color{green}188/188$ $\\color{green}+0.00\\%$

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