- Don't depend on math/libgmp-freebsd on FreeBSD <= 500023, use the base
libgmp instead. On FreeBSD > 500023 depend on math/libgmp4, as
math/libgmp-freebsd doesn't build on all architectures.
- Don't add PREFIX/include and PREFIX/lib to the search paths by default,
so on FreeBSD 4 the base libgmp is used. This protects from using one of
the libgmp ports if installed without registering a dependency on it.
- Keep from auto-detecting libgmp when WITHOUT_GMP is defined by specifying
the arithmetic to use.
Note: When using auto-detection and libgmp can't be found ndiff normally
would check for extended precision arithmetic first and succeed with it.
But using extended precision arithmetic causes the test suite to fail
(i.e. lots of differences) on all architectures expect sparc64. Therefore
specify double precision arithmetic for all other architectures when built
with WITHOUT_GMP.
Submitted by: marius
eb05069865