Update to GCC 13

The latest version of GCC.

Luckily this allows for a bunch of patches to be dropped - apart from
that, no significant change.

sysc/gcc-13.1.0/patches/libssp_nonshared.patch

@@ -0,0 +1,35 @@
+SPDX-FileCopyrightText: 2023 fosslinux <fosslinux@aussies.space>
+SPDX-FileCopyrightText: 2020 Timo Teräs <timo.teras@iki.fi>
+
+SPDX-License-Identifier: GPL-3.0-or-later
+
+The original motivation from this patch from Alpine Linux:
+
+Subject: [PATCH] Alpine musl package provides libssp_nonshared.a. We link to
+ it unconditionally, as otherwise we get link failures if some objects are
+ -fstack-protector built and final link happens with -fno-stack-protector.
+ This seems to be the common case when bootstrapping gcc, the piepatches do
+ not seem to fully fix the crosstoolchain and  bootstrap sequence wrt.
+ stack-protector flag usage.
+
+Which matches precisely the problem when compiling GCC with --enable-bootstrap
+in live-bootstrap.
+
+---
+ gcc/gcc.cc | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+diff --git gcc/gcc.cc gcc/gcc.cc
+index cc99d0b7aa1..c60a75371f8 100644
+--- gcc/gcc.cc
++++ gcc/gcc.cc
+@@ -1004,8 +1004,7 @@ proper position among the other output files.  */
+ 
+ #ifndef LINK_SSP_SPEC
+ #ifdef TARGET_LIBC_PROVIDES_SSP
+-#define LINK_SSP_SPEC "%{fstack-protector|fstack-protector-all" \
+-		       "|fstack-protector-strong|fstack-protector-explicit:}"
++#define LINK_SSP_SPEC "-lssp_nonshared"
+ #else
+ #define LINK_SSP_SPEC "%{fstack-protector|fstack-protector-all" \
+ 		       "|fstack-protector-strong|fstack-protector-explicit" \

sysc/gcc-13.1.0/patches/new-gettext.patch

@@ -0,0 +1,17 @@
+SPDX-FileCopyrightText: 2023 fosslinux <fosslinux@aussies.space>
+
+SPDX-License-Identifier: GPL-3.0-or-later
+
+In new gettext external is required for AM_GNU_GETTEXT.
+
+--- intl/configure.ac	2023-02-07 18:43:58.989786230 +1100
++++ intl/configure.ac	2023-02-07 18:43:02.182632631 +1100
+@@ -4,7 +4,7 @@
+ AC_CONFIG_HEADER(config.h)
+ AC_CONFIG_MACRO_DIR(../config)
+ AM_GNU_GETTEXT_VERSION(0.12.1)
+-AM_GNU_GETTEXT([], [need-ngettext])
++AM_GNU_GETTEXT([external], [need-ngettext])
+ 
+ # This replaces the extensive use of DEFS in the original Makefile.in.
+ AC_DEFINE(IN_LIBINTL, 1, [Define because this is libintl.])