Ports: Unbreak editline

This port uses incomplete function prototypes, which are no longer
supported as of C23.

Additionally, it failed to compile due to a missing <sys/select.h>
include. For some reason, there was already an upstream patch for this,
but it wasn't included in our patches.

Ports/editline/package.sh

@@ -8,3 +8,6 @@ config_sub_paths=('aux/config.sub')
 files=(
     "https://github.com/troglobit/editline/releases/download/${version}/editline-${version}.tar.gz#781e03b6a935df75d99fb963551e2e9f09a714a8c49fc53280c716c90bf44d26"
 )
+configopts=(
+    'CFLAGS=-std=c17'
+)

Ports/editline/patches/0001-include-sys-select.h-in-excallback.patch

@@ -0,0 +1,24 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Stephen Gregoratto <dev@sgregoratto.me>
+Date: Tue, 9 Jun 2020 00:21:11 +1000
+Subject: [PATCH] include <sys/select.h> in excallback
+
+Fixes an build issue when cross-compiling for SerenityOS[1]
+
+[1] https://github.com/SerenityOS/serenity
+---
+ examples/excallback.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/examples/excallback.c b/examples/excallback.c
+index 015132a992da46ba23c66649e7f12a0041133cf9..5a5efb327b64243ad85486392841c338fe498633 100644
+--- a/examples/excallback.c
++++ b/examples/excallback.c
+@@ -39,6 +39,7 @@ Jeff
+ 
+ #include <stdio.h>
+ #include <sys/types.h>
++#include <sys/select.h>
+ 
+ #ifdef HAVE_STDLIB_H
+ #include <stdlib.h>

Ports/editline/patches/ReadMe.md

@@ -0,0 +1,10 @@
+# Patches for editline on SerenityOS
+
+## `0001-include-sys-select.h-in-excallback.patch`
+
+include <sys/select.h> in excallback
+
+Fixes an build issue when cross-compiling for SerenityOS[1]
+
+[1] https://github.com/SerenityOS/serenity
+