internal/cabi: fix llvm.alloca for callInsrt

[visualfc]

fix #1227

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.17%. Comparing base (6de3bdc) to head (cd69092).
⚠️ Report is 53 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1231      +/-   ##
==========================================
+ Coverage   88.15%   88.17%   +0.01%     
==========================================
  Files          34       34              
  Lines        8470     8483      +13     
==========================================
+ Hits         7467     7480      +13     
  Misses        934      934              
  Partials       69       69              

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[luoliwoshang]

with this pr ,i try to use #1227 's POC to verify , it can work for me (darwin/arm64)