Libffi is updated to the latest stable version (v3.4.6) as the version
of libffi that was linked by the repository predates the introduction of
RISC-V processors (both 32 and 64 bits).
This is necessary as the packaged version of libffi used by the CI for
RISC-V 64 turned out to simply not work correctly, whilst a source-built
version of libffi worked just fine.
Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
This directory contains third-party, low-level C libraries and SDKs.
Libraries that do not target any specific platform are generally chosen
based on them being independent and efficient.