Log Message:
Update to libffi-3.0.6. From Aleksej Saushev, who's taking maintainership,
with an adjustment for info file handling.

Changes from 2.x appear to be large and aren't concisely anywhere I
can find. Changes since 3.0.0:

3.0.6 Jul-17-08
        Fix for closures on sh.
        Mark the sh/sh64 stack as non-executable.
        (both thanks to Kaz Kojima)

3.0.5 Apr-3-08
        Fix libffi.pc file.
        Fix #define ARM for IcedTea users.
        Fix x86 closure bug.

3.0.4 Feb-24-08
        Fix x86 OpenBSD configury.

3.0.3 Feb-22-08
        Enable x86 OpenBSD thanks to Thomas Heller, and
        x86-64 FreeBSD thanks to Björn König and Andreas Tobler.
        Clean up test instruction in README.

3.0.2 Feb-21-08
        Improved x86 FreeBSD support.
        Thanks to Björn König.

3.0.1 Feb-15-08
        Fix instruction cache flushing bug on MIPS.
        Thanks to David Daney.

3.0.0 Feb-15-08
        Many changes, mostly thanks to the GCC project.
        Cygnus Solutions is now Red Hat.