New comment by zlice on void-packages repository

https://github.com/void-linux/void-packages/pull/48480#issuecomment-1948832094

Comment:
ok so this works for x86, a64, a7l

```sh
post_configure() {
  if [ "$CROSS_BUILD" ]; then
    find -iname "*.ninja" -exec sed -i "{}" \
      -e "/rustc/s; --sysroot ${XBPS_CROSS_BASE}/usr;;g" \
      -e "s|-isystem/usr/include||g" \
      \;
  fi
}
```
it looks like ninja build has `-isystem/usr/include` for everything, so aarch64 gets x86_64's gnu stub.h ... which wants -32, which a64 doesn't have.

<details>
<summary>screenshot ninja build llvm_bindings</summary>

![systeminclude](https://github.com/void-linux/void-packages/assets/8009811/649fd673-0cf8-46ac-98a6-42afa7d417ed)

</details>