Change as_words() to return fixed-size std::span

[chfast]

No description provided.

[Copilot]

Pull request overview

This PR modernizes the as_words() API by changing it from returning raw pointers to returning fixed-size std::span objects, providing better type safety and compile-time size information.

Changes:

• Modified as_words() template functions to return std::span<uint64_t, N> and std::span<const uint64_t, N> instead of raw pointers
• Removed specialized uint128 overloads (now covered by the template)
• Updated all call sites to use .data() where raw pointers are needed
• Modernized test code to use std::ranges::generate with span's .subspan() method
• Changed parameter type from int to size_t for better type safety

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
include/intx/intx.hpp	Updated as_words() template functions to return fixed-size spans; removed redundant uint128 specializations; updated all usages to call .data() when raw pointers are needed
test/utils/random.cpp	Added as_words() overload for uint64_t& returning std::span<uint64_t, 1>; modernized random generation to use std::ranges::generate with .subspan(); changed parameter type from int to size_t

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.71%. Comparing base (7f8c0f3) to head (7e8354d).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #364      +/-   ##
==========================================
- Coverage   98.71%   98.71%   -0.01%     
==========================================
  Files          15       15              
  Lines        1867     1863       -4     
==========================================
- Hits         1843     1839       -4     
  Misses         24       24              

Flag	Coverage Δ
32bit	98.69% <100.00%> (-0.01%)	⬇️
gcc	98.70% <100.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
include/intx/intx.hpp	98.63% <100.00%> (-0.01%)	⬇️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.