[PATCH] nptl: add missing pthread-offsets.h

[Florian Weimer]

* Adhemerval Zanella:

> On 06/02/2020 15:45, Florian Weimer wrote:
>> * Andreas Schwab:
>> 
>>> All architectures using their own definition of struct
>>> __pthread_rwlock_arch_t need to provide their own pthread-offsets.h.
>> 
>> What's the context for this change?
>> 
>
> My understanding is tying the __PTHREAD_RWLOCK_FLAGS_OFFSET definition
> to a arch-specific file if the architecture overrides the generic
> __pthread_rwlock_arch_t definition.

Okay, then let me ask differently: Why hasn't this discrepancy shown
up in testing so far?