build of 3.4.0 failed in configure of libffi on alphaev6-dec-osf5.1

[Aaron Ucko]

Yep.

The bug seems to be in the definition of AC_FUNC_MMAP_BLACKLIST in
aclocal.m4, which could probably even get away with leaving out the
quotes provided that it first actually called
AC_CHECK_HEADERS(sys/mman.h) and AC_CHECK_FUNCS(mmap) rather than
assuming (incorrectly, it seems) that something had previously run
those checks.