msvc: fix detect_showincludes_prefix with MSBuild

[AJIOB]

The problem usually occurs when VS_UNICODE_OUTPUT is set. This is a @AudranDoublet #1835 and @exoosh #2483 fixes with working tests: thank you!

Should fix issues #1830 and #909

[codecov-commenter]

Codecov Report

❌ Patch coverage is 76.92308% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.24%. Comparing base (bbb8440) to head (a34b52a).

Files with missing lines	Patch %	Lines
src/compiler/msvc.rs	72.72%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2544   +/-   ##
=======================================
  Coverage   71.23%   71.24%           
=======================================
  Files          64       64           
  Lines       35597    35593    -4     
=======================================
- Hits        25359    25357    -2     
+ Misses      10238    10236    -2     

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[codspeed-hq]

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing AJIOB:VS_UNICODE_OUTPUT_fix_2 (a34b52a) with main (bbb8440)}

Summary

✅ 27 untouched benchmarks
🆕 27 new benchmarks
⏩ 2 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
🆕	Memory	cache_entry_batch_roundtrip	N/A	3.5 MB	N/A
🆕	Memory	build_workflow_initial	N/A	3.5 MB	N/A
🆕	Memory	lru_cache_eviction	N/A	186.1 KB	N/A
🆕	Memory	lru_cache_insert	N/A	372.1 KB	N/A
🆕	Memory	lru_hotcold_access_pattern	N/A	128 B	N/A
🆕	Memory	cache_entry_roundtrip_small	N/A	3.5 MB	N/A
🆕	Memory	time_macro_finder_no_macros	N/A	192 B	N/A
🆕	Memory	hash_header_file	N/A	192 B	N/A
🆕	Memory	decompression_high_ratio	N/A	3.3 MB	N/A
🆕	Memory	cache_entry_create_large	N/A	3.5 MB	N/A
🆕	Memory	build_workflow_rebuild	N/A	2.9 MB	N/A
🆕	Memory	cache_entry_roundtrip_large	N/A	4.3 MB	N/A
🆕	Memory	time_macro_finder_with_macros	N/A	192 B	N/A
🆕	Memory	hash_large_data	N/A	192 B	N/A
🆕	Memory	cache_key_generation	N/A	192 B	N/A
🆕	Memory	lru_cache_mixed_workload	N/A	222 KB	N/A
🆕	Memory	hash_multiple_files	N/A	128 B	N/A
🆕	Memory	cache_entry_create_small	N/A	3.5 MB	N/A
🆕	Memory	lru_realistic_eviction_pressure	N/A	4.9 MB	N/A
🆕	Memory	cache_entry_batch_create	N/A	3.5 MB	N/A
...	...	...	...	...	...

ℹ️ Only the first 20 benchmarks are displayed. Go to the app to view all benchmarks.

Footnotes

1. 2 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[sylvestre]

could you please add a test to make sure we don't regress? thanks

[AJIOB]

could you please add a test to make sure we don't regress? thanks

@sylvestre , done

[sylvestre]

could you please add a test to make sure we don't regress? thanks

@sylvestre , done

to make sure i understand, what you added in the CI was previously failing to build, right ?
thanks

[AJIOB]

Yes, it previously fails.