[SAOC 2024] Improve D Error Messages - Weekly Update #12

[Royal Simpson Pinto]

## Summary of Progress (December 2 – December 8)

This week, I worked on resolving platform-specific issues and 
finalizing the implementation of `verrors=context`, ensuring it 
works globally across all supported systems. I also addressed a 
buffer issue in the `splitLines` implementation and completed the 
pending work on the associated PR.

**PR:** feat(errors): make verrors=context global and update test 
outputs [#17085](https://github.com/dlang/dmd/pull/17085)

### What I Worked On

**Platform-Specific Issues Resolved:**
- **macOS:** Resolved all macOS-based failed targets, ensuring 
platform compatibility.
- **Windows:** Worked on and fixed the remaining failed targets 
for Windows.

**Buffer Issue in `splitLines`:**
- Encountered a buffer-related unit test failure in 
`compiler/src/dmd/root/string`.
- Fixed the issue by validating indices properly and handling 
edge cases in the `splitLines` implementation.
- Changes are included in the same PR.

**Finalizing the PR:**
- Completed all pending tasks for the PR.
- Ensured that `verrors=context` now works globally, similar to 
other compilers.

### Next Steps

- Address any feedback or suggestions provided for the PR.
- Work on any additional tasks that may arise during the review 
process.

With the PR completed, the compiler is now equipped to use 
`verrors=context` globally.