scrypt estimates the amount of available RAM, and ignores RLIMIT_DATA on
systems which have mmap. From tedu@ (http://mail.tarsnap.com/scrypt/msg00263.html):
"...this is the wrong thing to do for OpenBSD. On OpenBSD, rlimit_data
is applied to anonymous mmap (since that's now the heap) for
consistency. RLIMIT_RSS is a vestigal do nothing define."
Issue is fixed by reverting 2b478e7ce5
While here set COMPILER and COMPILER_LANGS to fix building on sparc64
and powerpc (from kmos@, and tested by kmos@ and cwen@).
OK cwen@, "patch looks good to me" tedu@
c677338f67