[NaCl SDK] nacl_io: seperate socket syscalls into thier own directory.

This change contains only renames. It allows us to
distingish between socket syscalls and others syscall
overrides, which helps us to identify overrides that
we should be aiming to eliminate.

Review URL: https://codereview.chromium.org/556533002

Cr-Commit-Position: refs/heads/master@{#293840}

native_client_sdk/src/libraries/nacl_io/library.dsc

@@ -65,69 +65,69 @@
         "stream/stream_event_emitter.cc",
         "stream/stream_fs.cc",
         "stream/stream_node.cc",
-        "syscalls/accept.c",
         "syscalls/access.c",
-        "syscalls/bind.c",
         "syscalls/cfgetispeed.c",
         "syscalls/cfgetospeed.c",
         "syscalls/cfsetispeed.c",
         "syscalls/cfsetospeed.c",
         "syscalls/cfsetspeed.c",
         "syscalls/chown.c",
-        "syscalls/connect.c",
         "syscalls/fchown.c",
         "syscalls/fcntl.c",
-        "syscalls/freeaddrinfo.c",
         "syscalls/ftruncate.c",
-        "syscalls/gai_strerror.c",
-        "syscalls/getaddrinfo.c",
         "syscalls/getcwd.c",
-        "syscalls/gethostbyname.c",
-        "syscalls/getnameinfo.c",
-        "syscalls/getpeername.c",
-        "syscalls/getsockname.c",
-        "syscalls/getsockopt.c",
         "syscalls/getwd.c",
-        "syscalls/herror.c",
-        "syscalls/hstrerror.c",
-        "syscalls/htonl.c",
-        "syscalls/htons.c",
-        "syscalls/inet_addr.c",
-        "syscalls/inet_aton.c",
-        "syscalls/inet_ntoa.c",
-        "syscalls/inet_ntop.cc",
-        "syscalls/inet_pton.c",
         "syscalls/ioctl.c",
         "syscalls/isatty.c",
         "syscalls/kill.c",
         "syscalls/killpg.c",
         "syscalls/lchown.c",
-        "syscalls/listen.c",
         "syscalls/mount.c",
-        "syscalls/ntohl.c",
-        "syscalls/ntohs.c",
         "syscalls/pipe.c",
         "syscalls/poll.c",
         "syscalls/realpath.c",
-        "syscalls/recv.c",
-        "syscalls/recvfrom.c",
-        "syscalls/recvmsg.c",
         "syscalls/remove.c",
         "syscalls/rename.c",
         "syscalls/select.c",
-        "syscalls/send.c",
-        "syscalls/sendmsg.c",
-        "syscalls/sendto.c",
-        "syscalls/setsockopt.c",
-        "syscalls/shutdown.c",
         "syscalls/sigaction.c",
         "syscalls/signal.c",
         "syscalls/sigpause.c",
         "syscalls/sigpending.c",
         "syscalls/sigset.c",
         "syscalls/sigsuspend.c",
-        "syscalls/socket.c",
-        "syscalls/socketpair.c",
+        "syscalls/socket/accept.c",
+        "syscalls/socket/bind.c",
+        "syscalls/socket/connect.c",
+        "syscalls/socket/freeaddrinfo.c",
+        "syscalls/socket/gai_strerror.c",
+        "syscalls/socket/getaddrinfo.c",
+        "syscalls/socket/gethostbyname.c",
+        "syscalls/socket/getnameinfo.c",
+        "syscalls/socket/getpeername.c",
+        "syscalls/socket/getsockname.c",
+        "syscalls/socket/getsockopt.c",
+        "syscalls/socket/herror.c",
+        "syscalls/socket/hstrerror.c",
+        "syscalls/socket/htonl.c",
+        "syscalls/socket/htons.c",
+        "syscalls/socket/inet_addr.c",
+        "syscalls/socket/inet_aton.c",
+        "syscalls/socket/inet_ntoa.c",
+        "syscalls/socket/inet_ntop.cc",
+        "syscalls/socket/inet_pton.c",
+        "syscalls/socket/listen.c",
+        "syscalls/socket/ntohl.c",
+        "syscalls/socket/ntohs.c",
+        "syscalls/socket/recv.c",
+        "syscalls/socket/recvfrom.c",
+        "syscalls/socket/recvmsg.c",
+        "syscalls/socket/send.c",
+        "syscalls/socket/sendmsg.c",
+        "syscalls/socket/sendto.c",
+        "syscalls/socket/setsockopt.c",
+        "syscalls/socket/shutdown.c",
+        "syscalls/socket/socket.c",
+        "syscalls/socket/socketpair.c",
         "syscalls/symlink.c",
         "syscalls/tcdrain.c",
         "syscalls/tcflow.c",