powerpc: More elision improvements

powerpc: More elision improvements

__lll_trylock_elision sets the adapt_count variable too
aggressively, and incorrectly on persistent aborts.  Taking
a cue from s390, adapt_count is only updated if the lock
is locked, or a persistent failure occurs.

In addition, the abort codes have been renumbered and
refactored for clarity.  As it stands, glibc only cares
if the abort is persistent or not.

All aborts are now persistent, excepting a busy lock.  This
includes changing _ABORT_NESTED_TRYLOCK into a persistent
abort.

	* sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
	(__lll_trylock_elision): Fix setting of adapt_count.
	* sysdeps/unix/sysv/linux/powerpc/htm.h
	(_ABORT_PERSISTENT): Define to clarify persistent aborts.
	(_ABORT_NESTED_TRYLOCK): Renumber, and make persistent.
	(_ABORT_SYSCALL): Renumber, and clarify definition.
	(_ABORT_LOCK_BUSY): Renumber, make non-persistent.