re: lib/49989 (libc++ fails to build with g++ 5.1 due to libpthread volatiles)

[matthew green <mrg%eterna.com.au@localhost>]

> well that didn't work.  ports are too divergent for us to be able to
> make a simple deduction on what __cpu_simplelock_t really looks like.

... the whole point of opaque types is to be opaque?  :-)