CLEANUP: drop support for USE_MY_ACCEPT4
The accept4() syscall has been present for a while now, there is no more
reason for maintaining our own arch-specific syscall implementation for
systems lacking it in libc but having it in the kernel.
diff --git a/Makefile b/Makefile
index 9596407..75ce791 100644
--- a/Makefile
+++ b/Makefile
@@ -39,7 +39,6 @@
# USE_LUA : enable Lua support.
# USE_FUTEX : enable use of futex on kernel 2.6. Automatic.
# USE_ACCEPT4 : enable use of accept4() on linux. Automatic.
-# USE_MY_ACCEPT4 : use own implementation of accept4() if glibc < 2.10.
# USE_PRCTL : enable use of prctl(). Automatic.
# USE_ZLIB : enable zlib library support.
# USE_SLZ : enable slz library instead of zlib (pick at most one).
@@ -290,7 +289,7 @@
USE_STATIC_PCRE USE_STATIC_PCRE2 USE_TPROXY USE_LINUX_TPROXY \
USE_LINUX_SPLICE USE_LIBCRYPT USE_CRYPT_H \
USE_GETADDRINFO USE_OPENSSL USE_LUA USE_FUTEX USE_ACCEPT4 \
- USE_MY_ACCEPT4 USE_ZLIB USE_SLZ USE_CPU_AFFINITY USE_TFO USE_NS \
+ USE_ZLIB USE_SLZ USE_CPU_AFFINITY USE_TFO USE_NS \
USE_DL USE_RT USE_DEVICEATLAS USE_51DEGREES USE_WURFL USE_SYSTEMD \
USE_OBSOLETE_LINKER USE_PRCTL USE_THREAD_DUMP USE_EVPORTS