Ports: Add libffi

Author: https://github.com/bugaevc
Commit: https://github.com/SerenityOS/serenity/commit/40fbdd4e9e0
Pull-request: https://github.com/SerenityOS/serenity/pull/3452

Ports/libffi/package.sh

@@ -0,0 +1,5 @@
+#!/bin/bash ../.port_include.sh
+port=libffi
+version=3.3
+useconfigure=true
+files="ftp://sourceware.org/pub/libffi/libffi-${version}.tar.gz libffi-${version}.tar.gz"

Ports/libffi/patches/fix-autoconf.patch

@@ -0,0 +1,12 @@
+--- a/config.sub	2019-10-31 17:49:54.000000000 +0300
++++ b/config.sub	2020-09-10 17:03:14.219589932 +0300
+@@ -1417,7 +1417,8 @@
+ 	      | -morphos* | -superux* | -rtmk* | -rtmk-nova* | -windiss* \
+ 	      | -powermax* | -dnix* | -nx6 | -nx7 | -sei* | -dragonfly* \
+ 	      | -skyos* | -haiku* | -rdos* | -toppers* | -drops* | -es* \
+-	      | -onefs* | -tirtos* | -phoenix* | -fuchsia* | -redox*)
++	      | -onefs* | -tirtos* | -phoenix* | -fuchsia* | -redox* \
++	      | -serenity* )
+ 	# Remember, each alternative MUST END IN *, to match a version number.
+ 		;;
+ 	-qnx*)