Indicate the removal of the README and carry out the
final update to the ports/ChangeLog.

This patch removes the ports/README now that ports is no longer
being used. It also adds a header to all ChangeLogs for all machines
that were moved to the main libc tree. The header indicates that the
ChangeLog is no longer used.

Cleanup and remove old lll_private_futex_wake macro and add
generic support for PI-aware futexes.

The lll_private_futex_wake function no longer exists. Instead use
lll_futex_make with LLL_PRIVATE as the last argument.

The generated assembly is simplified if we use r25,
the expected second argument to the function given the
calling convention.

[BZ #15215] This unifies various pthread_once architecture-specific
implementations which were using the same algorithm with slightly different
implementations.  It also adds missing memory barriers that are required for
correctness.

This patch moves the __PTHREAD_SPINS definition to arch specific header
since pthread_mutex_t layout is also arch specific.  This leads to no
need to defining __PTHREAD_MUTEX_HAVE_ELISION and thus removing of the
undefined compiler warning.