added several system call hooks for future sockets implementation

sysdeps/unix/make-syscalls.sh

 #! /bin/sh
 
 # Usage: make-syscalls.sh ../sysdeps/unix/common
 # Expects $sysdirs in environment.
 
 ##############################################################################
 
 # Syscall Signature Key Letters for BP Thunks:
 #
 # a: unchecked address (e.g., 1st arg to mmap)
@@ skipping 192 matching lines @@
     echo "       echo '#undef $base'; \\"
   done
   echo "\
          echo '$frtn$strong ( ); /* $args */'; \\
          echo 'libc_hidden_proto ($strong)'; \\"
   echo -n "      echo '$frtn$strong ("
   sprtr=
   for arg; do
     echo -n "$sprtr"
     case $arg in
-      [abIpP]*) echo -n "void *$arg";;
+      [abIpPBN]*) echo -n "void *$arg";;
       f*) echo -n "int $arg[2]";;
       i*) echo -n "int $arg";;
       n*) echo -n "size_t $arg";;
       [sS]*) echo -n "char *$arg";;
       V*) echo -n "unsigned char *$arg";;
       W*) echo -n "int *$arg";;
     esac
     sprtr=", "
   done
   echo ") {'; \\"
@@ skipping 175 matching lines @@
         ) | \$(COMPILE.c) -x c -o \$@ -"
 ### Use this for debugging intermediate output:
 ###     ) >\$(@:.ob=.c)
 ###     \$(subst -c,-E,\$(COMPILE.c)) -o \$(@:.ob=.ib) \$(@:.ob=.c)
 ###     \$(COMPILE.c) -x cpp-output -o \$@ \$(@:.ob=.ib)"
     echo endif
     ;;
   esac
 
 done