CLEANUP: remove support for USE_MY_SPLICE

The splice() syscall has been supported in glibc since version 2.5 issued
in 2006 and is present on supported systems so there's no need for having
our own arch-specific syscall definitions anymore.
diff --git a/Makefile b/Makefile
index 589cbf2..2019274 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,6 @@
 #   USE_EPOLL            : enable epoll() on Linux 2.6. Automatic.
 #   USE_KQUEUE           : enable kqueue() on BSD. Automatic.
 #   USE_EVPORTS          : enable event ports on SunOS systems. Automatic.
-#   USE_MY_SPLICE        : redefine the splice syscall if build fails without.
 #   USE_NETFILTER        : enable netfilter on Linux. Automatic.
 #   USE_PCRE             : enable use of libpcre for regex. Recommended.
 #   USE_PCRE_JIT         : enable JIT for faster regex on libpcre >= 8.32
@@ -282,7 +281,7 @@
 #### list of all "USE_*" options. These ones must be updated if new options are
 # added, so that the relevant options are properly added to the CFLAGS and to
 # the reported build options.
-use_opts = USE_EPOLL USE_KQUEUE USE_MY_SPLICE USE_NETFILTER                   \
+use_opts = USE_EPOLL USE_KQUEUE USE_NETFILTER                                 \
            USE_PCRE USE_PCRE_JIT USE_PCRE2 USE_PCRE2_JIT USE_POLL             \
            USE_PRIVATE_CACHE USE_THREAD USE_PTHREAD_PSHARED USE_BACKTRACE     \
            USE_STATIC_PCRE USE_STATIC_PCRE2 USE_TPROXY USE_LINUX_TPROXY       \
diff --git a/include/common/splice.h b/include/common/splice.h
deleted file mode 100644
index cd32eff..0000000
--- a/include/common/splice.h
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * include/common/splice.h
- * Splice definition for older Linux libc.
- *
- * Copyright 2000-2011 Willy Tarreau <w@1wt.eu>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation, version 2.1
- * exclusively.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- */
-
-#ifndef _COMMON_SPLICE_H
-#define _COMMON_SPLICE_H
-
-#if defined (__linux__) && defined(USE_LINUX_SPLICE)
-
-#include <errno.h>
-#include <unistd.h>
-#include <sys/syscall.h>
-#include <common/syscall.h>
-
-/* On recent Linux kernels, the splice() syscall may be used for faster data copy.
- * But it's not always defined on some OS versions, and it even happens that some
- * definitions are wrong with some glibc due to an offset bug in syscall().
- */
-
-#ifndef SPLICE_F_MOVE
-#define SPLICE_F_MOVE           0x1
-#endif
-
-#ifndef SPLICE_F_NONBLOCK
-#define SPLICE_F_NONBLOCK       0x2
-#endif
-
-#ifndef SPLICE_F_MORE
-#define SPLICE_F_MORE           0x4
-#endif
-
-#if defined(USE_MY_SPLICE)
-
-/* We'll define a syscall, so for this we need __NR_splice. It should have
- * been provided by syscall.h.
- */
-#ifndef __NR_splice
-#warning unsupported architecture, guessing __NR_splice=313 like x86...
-#define __NR_splice             313
-#endif /* __NR_splice */
-
-static inline _syscall6(int, splice, int, fdin, loff_t *, off_in, int, fdout, loff_t *, off_out, size_t, len, unsigned long, flags);
-
-#else
-/* use the system's definition */
-#include <fcntl.h>
-
-#endif /* USE_MY_SPLICE */
-
-#endif /* __linux__ && USE_LINUX_SPLICE */
-
-#endif /* _COMMON_SPLICE_H */
-
-/*
- * Local variables:
- *  c-indent-level: 8
- *  c-basic-offset: 8
- * End:
- */
diff --git a/include/common/syscall.h b/include/common/syscall.h
index 187d3f8..31070ab 100644
--- a/include/common/syscall.h
+++ b/include/common/syscall.h
@@ -80,25 +80,6 @@
 
 /* Define some syscall numbers that are sometimes needed */
 
-/* splice is even more recent than epoll. It appeared around 2.6.18 but was
- * not in libc for a while.
- */
-#ifndef __NR_splice
-#if defined(__powerpc__) || defined(__powerpc64__)
-#define __NR_splice             283
-#elif defined(__sparc__) || defined(__sparc64__)
-#define __NR_splice             232
-#elif defined(__x86_64__)
-#define __NR_splice             275
-#elif defined(__alpha__)
-#define __NR_splice             468
-#elif defined (__i386__)
-#define __NR_splice             313
-#elif defined(__s390__) || defined(__s390x__)
-#define __NR_splace		306
-#endif /* $arch */
-#endif /* __NR_splice */
-
 #endif /* __linux__ */
 #endif /* _COMMON_SYSCALL_H */
 
diff --git a/src/raw_sock.c b/src/raw_sock.c
index ca22d20..f17d45d 100644
--- a/src/raw_sock.c
+++ b/src/raw_sock.c
@@ -43,7 +43,6 @@
 
 
 #if defined(USE_LINUX_SPLICE)
-#include <common/splice.h>
 
 /* A pipe contains 16 segments max, and it's common to see segments of 1448 bytes
  * because of timestamps. Use this as a hint for not looping on splice().