Log Message:
libffcall: update to 2.5.

New in 2.5:

* Added support for the following platforms:
  (Previously, a build on these platforms failed.)
  - loongarch64: Linux with lp64d ABI.
  - riscv64: Linux with musl libc.
  - hppa: Linux.
  - powerpc: FreeBSD, NetBSD.
  - powerpc64: FreeBSD.
  - powerpc64le: FreeBSD.
  - arm: Android.

* Fixed support for the following platforms:
  (Previously, a build on these platforms appeared to succeed but was buggy.)
  - ia64: Linux.
  - arm64: OpenBSD.

* Simplified the environmental requirements (the library no longer allocates
  a temporary file in /tmp) on the following platforms:
  - Linux.
  - macOS.
  - FreeBSD 13 and newer.
  - NetBSD 8 and newer.