Update Solaris SPARC compile options.
Update Solaris SPARC compile options.

This solves part of https://github.com/knu/ruby-unf_ext/issues/32 based almost entirely on the solution that @MarkGibbons provided. Since SPARC is technically a 64bit operating system by default, this seems reasonable.

Signed-off-by: Scott Hain <54f99c3933fb11a028e0e31efcf2f4c9707ec4bf@chef.io>

knu/ruby-unf_ext,knu/ruby-unf_ext