feat: add math/base/special/exp2f

[whizzel]

Ref: #649 .

Description

What is the purpose of this pull request?

This pull request:

• Adds the complete implementation for math/base/special/exp2f

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Add C implementations to base special math functions (tracking issue) #649

Questions

Any questions for reviewers of this pull request?

No.

Other

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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?

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• No

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

Disclosure

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{{TODO: add disclosure if applicable}}

---

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[whizzel]

/stdlib update-copyright-years

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/exp2f	$\color{green}344/344$ $\color{green}+100.00%$	$\color{green}19/19$ $\color{green}+100.00%$	$\color{green}4/4$ $\color{green}+100.00%$	$\color{green}344/344$ $\color{green}+100.00%$

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