nacl_io: Add inet_pton() and ip6addr_* consts.

native_client_sdk/src/libraries/nacl_io/library.dsc

 {
   'TOOLS': ['newlib', 'glibc', 'pnacl', 'linux'],
   'SEARCH': [
     '.',
     'pepper',
     '../third_party/newlib-extras',
     'include',
   ],
   'TARGETS': [
     {
       'NAME' : 'nacl_io',
       'TYPE' : 'lib',
       'SOURCES' : [
         'dbgprint.c',
         "event_emitter.cc",
         "event_emitter_pipe.cc",
         "event_emitter_stream.cc",
         "event_emitter_tcp.cc",
         "event_emitter_udp.cc",
         "event_listener.cc",
         "fifo_char.cc",
         "fifo_packet.cc",
         "getdents_helper.cc",
         "h_errno.cc",
         "host_resolver.cc",
+        "in6_addr.c",
         "kernel_handle.cc",
         "kernel_intercept.cc",
         "kernel_object.cc",
         "kernel_proxy.cc",
         "kernel_wrap_dummy.cc",
         "kernel_wrap_glibc.cc",
         "kernel_wrap_newlib.cc",
         "kernel_wrap_win.cc",
         "mount.cc",
         "mount_dev.cc",
@@ skipping 44 matching lines @@
         "syscalls/getpeername.c",
         "syscalls/getsockname.c",
         "syscalls/getsockopt.c",
         "syscalls/getwd.c",
         "syscalls/herror.c",
         "syscalls/hstrerror.cc",
         "syscalls/htonl.c",
         "syscalls/htons.c",
         "syscalls/inet_ntoa.cc",
         "syscalls/inet_ntop.cc",
+        "syscalls/inet_pton.c",
         "syscalls/ioctl.c",
         "syscalls/isatty.c",
         "syscalls/kill.c",
         "syscalls/killpg.c",
         "syscalls/lchown.c",
         "syscalls/link.c",
         "syscalls/listen.c",
         "syscalls/lstat.c",
         "syscalls/mkdir.c",
         # Not called mount.c to avoid object file naming conflict with
@@ skipping 162 matching lines @@
         "all_interfaces.h",
         "define_empty_macros.h",
         "undef_macros.h",
       ],
       'DEST': 'include/nacl_io/pepper',
     }
   ],
   'DEST': 'src',
   'NAME': 'nacl_io',
 }