Port of 6d0c87602f ("llvmPackages_15.llvm: add in a missing check
dep").
I did not include the sysctl nativeCheckInputs change from that
commit, as it looks like it was included by mistake and was supposed
to be in c7231c0b6d ("llvmPackages_15.llvm: run the tests on macOS").
I've also included the doCheck default from that commit (without the
change to run on non-Linux), as 6d0c87602f just set it to true.