Switch from using 'nacl_main' to 'main' entry point

ports/twm/build.sh

 # Copyright (c) 2014 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 EXECUTABLES="twm${NACL_EXEEXT}"
-NACLPORTS_CPPFLAGS+=" -Dmain=nacl_main"
 
 NACLPORTS_LIBS+="\
-  -lXext -lXmu -lSM -lICE -lXt -lX11 -lxcb -lXau ${NACL_CLI_MAIN_LIB}"
+  -lXext -lXmu -lSM -lICE -lXt -lX11 -lxcb -lXau"
 
+EnableCliMain
 EnableGlibcCompat
 
 if [ "${TOOLCHAIN}" = "pnacl" -o "${TOOLCHAIN}" = "clang-newlib" ]; then
   NACLPORTS_CFLAGS+=" -Wno-return-type -Wno-parentheses -Wno-dangling-else"
   NACLPORTS_CPPFLAGS+=" -std=gnu89"
 fi
 
 BuildStep() {
   RC=deftwmrc.c
   rm -f ${RC}
@@ skipping 19 matching lines @@
 PublishStep() {
   MakeDir ${PUBLISH_DIR}
   ChangeDir ${PUBLISH_DIR}
   LogExecute cp -f ${BUILD_DIR}/twm${NACL_EXEEXT} twm_${NACL_ARCH}${NACL_EXEEXT}
   LogExecute python ${NACL_SDK_ROOT}/tools/create_nmf.py\
      twm_*${NACL_EXEEXT} -s . -o twm.nmf
   LogExecute python ${TOOLS_DIR}/create_term.py -n twm twm.nmf
   InstallNaClTerm .
   LogExecute cp -f ${START_DIR}/*.js .
 }