Add new tests signal{9,10} in t_ptrace_wait{,3,4,6,id,pid}

signal9:
    Verify that masking SIGTRAP in tracee does not stop tracer from
    catching PTRACE_LWP_CREATE breakpoint

signal10:
    Verify that masking SIGTRAP in tracee does not stop tracer from
    catching PTRACE_LWP_EXIT breakpoint

Both tests are broken and linked with PR kern/51918.

Sponsored by <The NetBSD Foundation>

(kamil)