[committed] hppa: Drop 16-byte pthread lock alignment

[Florian Weimer]

* John David Anglin:

> hppa: Drop 16-byte pthread lock alignment
>
> Linux threads were removed about 12 years ago and the current
> nptl implementation only requires 4-byte alignment for pthread
> locks.
>
> The 16-byte alignment causes various issues. For example in
> building ignition-msgs, we have:
>
> /usr/include/google/protobuf/map.h:124:37: error: static assertion failed
>   124 |   static_assert(alignof(value_type) <= 8, "");
>       |                 ~~~~~~~~~~~~~~~~~~~~^~~~
>
> This is caused by the 16-byte pthread lock alignment.

This was done deliberately to preserve ABI.  This change needs a mass
rebuild because struct offsets after pthread_mutex_t members are
likely to change.