Ports: Add TiMidity++

Also add it as a dependency for the `SDL_mixer` and `SDL2_mixer` ports.

Eawpats GUS patches are installed as part of the port, because without
patches TiMidity++ is not able to generate any sound. The license for
these is "fameware", credit to Andrew Suffield:

  https://lists.debian.org/debian-legal/2002/09/msg00137.html

Ports/timidity/package.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env -S bash ../.port_include.sh
+port='timidity'
+useconfigure='true'
+version='2.15.0'
+files="https://netcologne.dl.sourceforge.net/project/timidity/TiMidity%2B%2B/TiMidity%2B%2B-${version}/TiMidity%2B%2B-${version}.tar.xz timidity-${version}.tar.xz 9eaf4fadb0e19eb8e35cd4ac16142d604c589e43d0e8798237333697e6381d39
+https://www.quaddicted.com/files/idgames/sounds/eawpats.zip eawpats.zip.no_extract 19087fa4a40e25ec39a09cffcc9f775fc22d88bc971a7a9831e075cdae2ee1e3"
+auth_type='sha256'
+workdir="TiMidity++-${version}"
+use_fresh_config_sub='true'
+config_sub_paths=('autoconf/config.sub')
+depends=()
+configopts=(
+    'lib_cv___va_copy=no'
+    'lib_cv_va_copy=no'
+    'lib_cv_va_val_copy=no'
+)
+
+post_install() {
+    # Unpack Eawpats
+    eaw_pats_dir='/usr/local/share/eawpats'
+    eaw_pats_host_dir="${SERENITY_INSTALL_ROOT}${eaw_pats_dir}"
+    mkdir -p "${eaw_pats_host_dir}"
+    run unzip -qo -d "${eaw_pats_host_dir}" '../eawpats.zip.no_extract'
+
+    # Set up timidity.cfg
+    timidity_cfg_path="${SERENITY_INSTALL_ROOT}/etc/timidity.cfg"
+    mkdir -p "$(dirname ${timidity_cfg_path})"
+    cp "${eaw_pats_host_dir}/timidity.cfg" "${timidity_cfg_path}"
+    sed -i "s#^dir .*#dir ${eaw_pats_dir}#g" "${timidity_cfg_path}"
+}

Ports/timidity/patches/0001-Calculate-Newton-coefficients-on-the-fly.patch

@@ -0,0 +1,60 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jelle Raaijmakers <jelle@gmta.nl>
+Date: Thu, 1 Sep 2022 13:47:34 +0200
+Subject: [PATCH] Calculate Newton coefficients on the fly
+
+Since we are cross-compiling, we do not get a binary we can run on the
+host that is able to generate `newton_table.c`, so fall back to the old
+way of generating the table.
+---
+ timidity/Makefile.in | 2 --
+ timidity/resample.c  | 5 +----
+ 2 files changed, 1 insertion(+), 6 deletions(-)
+
+diff --git a/timidity/Makefile.in b/timidity/Makefile.in
+index e4ee43c..a93105e 100644
+--- a/timidity/Makefile.in
++++ b/timidity/Makefile.in
+@@ -1956,8 +1956,6 @@ uninstall-am: uninstall-binPROGRAMS uninstall-info-am
+ version.$(OBJEXT): version.c ../configure
+ 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(CFLAGS) -c $(srcdir)/version.c
+ 
+-resample.c: newton_table.c
+-
+ @VCPP_TRUE@newton_table.c: calcnewt$(EXEEXT)
+ @VCPP_TRUE@	./calcnewt $@
+ 
+diff --git a/timidity/resample.c b/timidity/resample.c
+index cd6b8e6..a878526 100644
+--- a/timidity/resample.c
++++ b/timidity/resample.c
+@@ -46,7 +46,6 @@
+ 
+ /* for start/end of samples */
+ static float newt_coeffs[58][58] = {
+-#include "newton_table.c"
+ };
+ 
+ int sample_bounds_min, sample_bounds_max; /* min/max bounds for sample data */
+@@ -468,7 +467,6 @@ void free_gauss_table(void)
+ 	gauss_table[0] = NULL;
+ }
+ 
+-#if 0 /* NOT USED */
+ /* the was calculated statically in newton_table.c */
+ static void initialize_newton_coeffs(void)
+ {
+@@ -499,12 +497,11 @@ static void initialize_newton_coeffs(void)
+     	for (j = 0, sign = pow(-1, i); j <= i; j++, sign *= -1)
+     	    newt_coeffs[i][j] *= sign;
+ }
+-#endif /* NOT USED */
+ 
+ /* initialize the coefficients of the current resampling algorithm */
+ void initialize_resampler_coeffs(void)
+ {
+-    /* initialize_newton_coeffs(); */
++    initialize_newton_coeffs();
+     initialize_gauss_table(gauss_n);
+     /* we don't have to initialize newton table any more */
+ 

Ports/timidity/patches/ReadMe.md

@@ -0,0 +1,10 @@
+# Patches for timidity on SerenityOS
+
+## `0001-Calculate-Newton-coefficients-on-the-fly.patch`
+
+Calculate Newton coefficients on the fly
+
+Since we are cross-compiling, we do not get a binary we can run on the
+host that is able to generate `newton_table.c`, so fall back to the old
+way of generating the table.
+