Ports: Add libwebp

This library includes webp converter to other formats as well and could
be used as reference implementation for performance improvements.

Ports/libwebp/patches/0001-libtool-Enable-shared-library-support-for-SerenityOS.patch

@@ -0,0 +1,78 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Liav A <liavalb@gmail.com>
+Date: Fri, 1 Sep 2023 23:44:19 +0300
+Subject: [PATCH] libtool: Enable shared library support for SerenityOS
+
+For some odd reason, libtool handles the configuration for shared
+libraries entirely statically and in its configure script. If no
+shared library support is "present", building shared libraries is
+disabled entirely.
+
+Fix that by just adding the appropriate configuration options for
+`serenity`. This allows us to finally create dynamic libraries
+automatically using libtool, without having to manually link the
+static library into a shared library.
+
+This patch here is a bit more elaborate for other ports, as libintl's
+configure includes the code for detecting dynamic linker characteristics
+twice, and it also queries the C++ compiler for shared library support.
+
+Co-Authored-By: Daniel Bertalan <dani@danielbertalan.dev>
+---
+ configure | 22 ++++++++++++++++++++++
+ 1 file changed, 22 insertions(+)
+
+diff --git a/configure b/configure
+index d4507aa5761e23c732cc219af4c1c119055cb377..884c76f4da0d8d2640b9fa66cd869816ff35c927 100755
+--- a/configure
++++ b/configure
+@@ -5635,6 +5635,10 @@ else $as_nop
+     lt_cv_sys_max_cmd_len=8192
+     ;;
+ 
++  serenity*)
++    lt_cv_deplibs_check_method=pass_all
++    ;;
++
+   osf*)
+     # Dr. Hans Ekkehard Plesser reports seeing a kernel panic running configure
+     # due to this test when exec_disable_arg_limit is 1 on Tru64. It is not
+@@ -9224,6 +9228,10 @@ lt_prog_compiler_static=
+       lt_prog_compiler_pic='-fPIC -shared'
+       ;;
+ 
++    serenity)
++      lt_prog_compiler_can_build_shared=yes
++      ;;
++
+     sysv4*MP*)
+       if test -d /usr/nec; then
+ 	lt_prog_compiler_pic=-Kconform_pic
+@@ -10067,6 +10075,10 @@ _LT_EOF
+       fi
+       ;;
+ 
++    serenity*)
++      ld_shlibs=no
++      ;;
++
+     solaris*)
+       if $LD -v 2>&1 | $GREP 'BFD 2\.8' > /dev/null; then
+ 	ld_shlibs=no
+@@ -11474,6 +11486,16 @@ beos*)
+   dynamic_linker="$host_os ld.so"
+   shlibpath_var=LIBRARY_PATH
+   ;;
++serenity*)
++  version_type=linux
++  need_lib_prefix=no
++  need_version=no
++  library_names_spec='${libname}${release}${shared_ext}${versuffix} ${libname}${release}${shared_ext}${major} ${libname}${shared_ext}'
++  soname_spec='${libname}${release}${shared_ext}${major}'
++  shlibpath_var=LD_LIBRARY_PATH
++  shlibpath_overrides_runpath=no
++  dynamic_linker='SerenityOS LibELF'
++  ;;
+ 
+ bsdi[45]*)
+   version_type=linux # correct to gnu/linux during the next big refactor