lowlevellock systemtap probes: inconsistencies with documentation

[Torvald Riegel]

DESIGN-systemtap-probes.txt lists three probes for lowlevlelock:
lll_lock_wait lll_lock_wait_private lll_futex_wake

The first two are present in x86_64 and x86 asm code.  However, they are
not present in the generic code for lowlevellock.  We want to eventually
get towards using the generic code on all arcs.  Do we need to preserve
the probes, or should we just remove them on x86?

I couldn't find a lll_futex_wake probe.  Did it get lost and do we need
to restore it for some reason, or is DESIGN-systemtap-probes.txt simply
outdated?  Is there another list of probes that we'd have to update?