feat: add C implementation for math/base/special/beta

[gunjjoshi]

Description

What is the purpose of this pull request?

This pull request:

• adds C implementation for math/base/special/beta.

double stdlib_base_beta( const double a, const double b );

Related Issues

Does this pull request have any related issues?

This pull request:

• resolves a part of [RFC]: Add C implementations to base special math functions (tracking issue) #649.

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.

We might not get 100% code coverage here, due to some lines of code being impossible to reach, such as the condition x === 0.0 in the evalrational function.

Checklist

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

• Read, understood, and followed the contributing guidelines.

---

@stdlib-js/reviewers

[kgryte]

@gunjjoshi Just checking. Did you compare to the latest Boost implementation? The source in main.c says v1.64, but I believe Boost has released new versions since then and it would be good to ensure we have the latest source.

[gunjjoshi]

@kgryte I looked over the latest Boost implementation, i.e., v1.85. After comparing both v1.85 and v1.64, it seems that there is no difference in their implementations. Shall I just update the version in main.c then?

[kgryte]

Yes, you can update the version in both the JavaScript and C implementation.

[Planeshifter]

Looks all good to me, thanks @gunjjoshi!