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

ports/m4/nacl.patch

 diff --git a/configure b/configure
 --- a/configure
 +++ b/configure
 @@ -7563,7 +7563,6 @@ $as_echo "$gl_cv_cc_uninitialized_supported" >&6; }
      -Wattributes \
      -Wbad-function-cast \
      -Wbuiltin-macro-redefined \
 -    -Wcast-align \
      -Wchar-subscripts \
      -Wclobbered \
@@ skipping 164 matching lines @@
    { "os2",      "__os2__",      "" },
  #endif
 -#if !UNIX && !W32_NATIVE && !OS2
 +#if !UNIX && !W32_NATIVE && !OS2 && !defined(__native_client__)
  # warning Platform macro not provided
  #endif
    { NULL,       "__gnu__",      "" },
 diff --git a/src/m4.c b/src/m4.c
 --- a/src/m4.c
 +++ b/src/m4.c
-@@ -362,7 +362,11 @@ process_file (const char *name)
- #endif
- 
- int
-+#if defined(__native_client__)
-+nacl_main (int argc, const char *argv[])
-+#else
- main (int argc, char *const *argv)
-+#endif
- {
-   struct sigaction act;
-   macro_definition *head;       /* head of deferred argument list */
 @@ -403,7 +407,11 @@ main (int argc, char *const *argv)
    sigemptyset (&act.sa_mask);
    /* One-shot - if we fault while handling a fault, we want to revert
       to default signal behavior.  */
 +#if defined(__native_client__) && defined(_NEWLIB_VERSION)
 +  act.sa_flags = SA_NODEFER;
 +#else
    act.sa_flags = SA_NODEFER | SA_RESETHAND;
 +#endif
    act.sa_handler = fault_handler;
    sigaction (SIGSEGV, &act, NULL);
    sigaction (SIGABRT, &act, NULL);