build: dev support checkLinkArgs/CheckLLFiles/GenLLFiles

[visualfc]

move env to build -tags=dev flags

-check-linkargs
-check-llfiles
-gen-llfiles

LLGO_CHECK
LLGO_CHECK_LINKARGS

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.15%. Comparing base (6de3bdc) to head (96c7afc).
⚠️ Report is 55 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1228   +/-   ##
=======================================
  Coverage   88.15%   88.15%           
=======================================
  Files          34       34           
  Lines        8470     8470           
=======================================
  Hits         7467     7467           
  Misses        934      934           
  Partials       69       69           

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