fix(double): op_mod for subnormal double (#1303)

[liuly0322]

Closes #1303

Rewrite op_mod for Double using MUSL implementation (src/math/fmod.c). The origin license of the file is in commit b69f695.

More tests are provided.

[peter-jerry-ye-code-review]

‼️ This code review is generated by a bot. Please verify the content before trusting it.

Here are three observations from the provided git diff output:

1. Inconsistent Pluralization in NOTICE File:

   • The line File float/exp.mbt, float/log.mbt, and double/scalbn.mbt is adapted from was changed to include double/mod_nonjs.mbt, but the verb "is" was not updated to "are" to match the plural subject. The corrected line should be: Files float/exp.mbt, float/log.mbt, double/mod_nonjs.mbt, and double/scalbn.mbt are adapted from.

2. Potential Issue in mod_nonjs.mbt:

   • In the op_mod function, the line return x * y / (x * y) is used to handle cases where y is zero, NaN, or x is infinity. This expression will always evaluate to 1.0 unless x or y is NaN or infinity, which might not be the intended behavior. It would be clearer and more correct to directly return not_a_number in these cases.

3. Redundant Test Cases in mod_test.mbt:

   • The test case inspect!(5.75 % 5.75, content="0") is redundant because it tests the same scenario as inspect!(8.0 % 4.0, content="0") and inspect!(15.0 % 3.0, content="0"), where the result of the modulo operation is zero. While it's good to have multiple test cases, they should cover different scenarios to ensure comprehensive testing. Consider adding more diverse test cases instead of repeating similar ones.

These observations highlight areas where improvements can be made for clarity, correctness, and efficiency.

[coveralls]

Pull Request Test Coverage Report for Build 4362

Details

• 22 of 22 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 83.306%

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Totals
Change from base Build 4360:	0.2%
Covered Lines:	4651
Relevant Lines:	5583

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💛 - Coveralls

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Files not reviewed (3)

• NOTICE: Language not supported
• double/mod_nonjs.mbt: Language not supported
• double/mod_test.mbt: Language not supported

[tonyfettes]

LGTM