minimal gcov gcda emitting emulation for wasm target

[nihui]

No description provided.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.37%. Comparing base (2389090) to head (611aa58).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff            @@
##           master    #5903    +/-   ##
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  Coverage   95.37%   95.37%            
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  Files         818      818            
  Lines      268009   268365   +356     
========================================
+ Hits       255610   255966   +356     
  Misses      12399    12399            

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[Copilot]

Copilot reviewed 2 out of 5 changed files in this pull request and generated no comments.

Files not reviewed (3)

• CMakeLists.txt: Language not supported
• src/CMakeLists.txt: Language not supported
• src/platform.h.in: Language not supported

Comments suppressed due to low confidence (1)

src/simplegcov.cpp:70

• [nitpick] The local variable 'g' in this context shadows the global variable 'g'. Consider renaming it (e.g. to 'fileInfo') to improve clarity.

const gcda_info& g = gcdas[i];