[futex] Soft transition to updated futex API: Step 4

Perform a soft transition to an updated futex syscall API which
adds support for building sync objects which implement priority
inherance out of futexes.

The steps involved in this transition are as follows.
1) Introduce new versions of all syscalls whose signatures are
   changing with a _deprecated suffix.  These versions are simple
   passthrus to the old functionality.
2) Update all non-zircon users to use the _deprecated versions.
3) Update the syscall signatures in zircon, and update all zircon
   users.  Retain the deprecated flavors for now.
4) Update all non-zircon users to use new versions of the syscalls.
5) Remove the _deprecated versions of the syscalls from zircon.

Step #1 was completed with I61ce7ec228cf0da847d8f1065b368edd624bd195
Step #2 was completed with I069e81a3f46e08c2fe2b0d298acf472de5031f7e
                       and I590302177a9e5e4bd532367373dc61bb652f3bc2
Step #3 was completed with I4453ffcbd62932d71ea1afdcf250d7fdc561e817
This is part of step #4.

Tests: build garnet, runtests on NUC
Change-Id: Ifb05eeeccf94d4e54f6be0811be4304a002504ba
3 files changed