Errors in libffi-types.lisp on aarch64

[Michael Graffam]

libffi-types.lisp seems in error. Installed the quicklisp version. The FFI_DEFAULT_ABI portion has:

#-(or freebsd windows)
(cenum abi
 ((:default-abi "FFI_DEFAULT_ABI"))
 #-x86-64
 ((:sysv "FFI_SYSV"))
 ((:unix64 "FFI_UNIX64")))

On SBCL 2.0.11 / Linux / aarch64 this is picked up as applying the last :unix64 part.

The FFI_DEFAULT_ABI on Linux / aarch64 is FFI_SYSV.

Commenting out the :unix64 and closing up the sexp as so:

#-(or freebsd windows)
(cenum abi
 ((:default-abi "FFI_DEFAULT_ABI"))
 #-x86-64
 ((:sysv "FFI_SYSV")))
;; ((:unix64 "FFI_UNIX64")))

This allows things to build correctly. I used the result to compile MAGICL, and ran all tests successfully.