Type-checking not fully disabled for guests on host

[dstolfa]

When running a script such as:

dtrace -E -n 'vm*:syscall:::entry { x = copyinstr(curthread->td_proc->p_comm); }'

we get the following error:

dtrace: invalid probe specifier vm*:syscall:::entry { x = copyinstr(curthread->td_proc->p_comm); }: in action list: operands have incompatible types: "<none>" = "<none>"

This is likely caused by the parser still trying to type-check things it shouldn't in the host.