`fatal error: Too many open files` during building on `macOS`

For some reason since https://github.com/HaxeFoundation/hxcpp/commit/aafc1d4344e1ab1ab6a5a9dbf967b1bbfc5bd4ed, `macOS` compile seems to give this weird fatal error `Too many open files` after some closer inspection, it seems that `Terminal.app` is defaulting the `ulimit -n` to 256 which `hxcpp` seems to not like, `VSCode` seems to default it to a much bigger value, after doing `ulimit -n 512` the fatal error completely disappeared, i think the best solution in this case is to make the `BuildTool` set `ulimit -n` to a bigger value if the current value is too small.

I have to mention that im encountering all this on `macOS` Tahoe 26.5.2 on a `MacBook Pro M5`.

Start at the BuildTool entry point and reproduce the build from macOS Terminal.app with its default ulimit -n value of 256, then compare it with a shell using ulimit -n 512. Done means the affected build completes without requiring the user to raise the limit manually.

Written by the indexing model from the issue text.