A web build containing a .jslib with pointer arguments throws a TypeError when Wasm64 is used

How to reproduce:

1. Open the attached project “IN-151234”
2. In the Build Profiles window, ensure that the “Web” profile is selected and that the “Probe” Scene is added to the Scene List
3. In “Project Settings → Player → Publishing Settings”, ensure that Initial Memory Size is set to 2048 and the Maximum Memory Size is set to 8192
4. Build and run the project
5. Observe the browser

Actual result: A “TypeError: can't convert BigInt to number” error is thrown
Expected result: No errors are thrown and “[PROBE] RESULT pass=2 fail=0” is printed to the browser’s console

Reproducible with: 6000.6.0b2, 6000.6.0f1, 6000.7.0a6
Could not test with: 6000.0.83f1, 6000.3.23f1, 6000.6.0b1 (Wasm64 is not available)

Reproducible on: macOS 26.6.2 (M4 Max)
Not reproducible on: No other environments tested