fix extract_type_parameters regarding primitive types

[xunilrj]

Description

This PR is part of #5110. It fixes a problem that improves the usability of slices.

When a method is returned from the "method resolution algorithm", if any generic is involved, it is returned as its generic form. So for example, if a method len is called on Vec<u8>, we return something like fn len(self: Vec<T>).

Later we monomorphize T into u8. To do that we run a "pattern match" to realize that we need to replace T with u8.

In this case, the bug was that we were not considering that some primitive types have "implicit type parameters".

This was found whilst creating more tests for #6933, because I was not able to call the len method defined for slices as:

impl<T> &[T] {
    pub fn len(self) -> u64 {
        ...
    }
}

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[codspeed-hq]

CodSpeed Performance Report

Merging #6965 will not alter performance

_{Comparing xunilrj/fix-extract-type-parameters (ae3eddb) with master (597ecfb)}

Summary

✅ 22 untouched benchmarks

[IGI-111]

Congrats on figuring this one out 🕵️