Ports: Add pkgconf (#3757)

Ports/pkgconf/package.sh

@@ -0,0 +1,12 @@
+#!/bin/bash ../.port_include.sh
+port=pkgconf
+version=1.7.3
+files="https://distfiles.dereferenced.org/pkgconf/pkgconf-1.7.3.tar.xz pkgconf-1.7.3.tar.xz"
+useconfigure=true
+usr_local=$SERENITY_ROOT/Build/Root/usr/local/
+configopts="--prefix=/usr/local --with-pkg-config-dir=/usr/local/lib/pkgconfig"
+
+post_install() {
+    mkdir -p $SERENITY_ROOT/Build/Root/bin
+    ln -sf /usr/local/bin/pkgconf $SERENITY_ROOT/Build/Root/usr/local/bin/pkg-config
+}

Ports/pkgconf/patches/build-system.patch

@@ -0,0 +1,12 @@
+--- pkgconf-1.7.3/config.sub.orig	2020-10-13 18:51:42.736398026 +1100
++++ pkgconf-1.7.3/config.sub	2020-10-13 18:51:45.953064825 +1100
+@@ -1393,7 +1393,8 @@
+ 	      | -os2* | -vos* | -palmos* | -uclinux* | -nucleus* \
+ 	      | -morphos* | -superux* | -rtmk* | -rtmk-nova* | -windiss* \
+ 	      | -powermax* | -dnix* | -nx6 | -nx7 | -sei* | -dragonfly* \
+-	      | -skyos* | -haiku* | -rdos* | -toppers* | -drops* | -es* | -tirtos*)
++	      | -skyos* | -haiku* | -rdos* | -toppers* | -drops* | -es* | -tirtos* \
++      	      | -serenity*)
+ 	# Remember, each alternative MUST END IN *, to match a version number.
+ 		;;
+ 	-qnx*)