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

ports/grep/nacl.patch

 diff --git a/configure b/configure
 --- a/configure
 +++ b/configure
 @@ -33696,7 +33696,6 @@ printf "%s\n" "$gl_cv_cc_uninitialized_supported" >&6; }
      -Wattributes \
      -Wbad-function-cast \
      -Wbuiltin-macro-redefined \
 -    -Wcast-align \
      -Wchar-subscripts \
      -Wclobbered \
@@ skipping 136 matching lines @@
 +++ b/src/Makefile.in
 @@ -1259,7 +1259,7 @@ clean-binPROGRAMS:
  
  grep$(EXEEXT): $(grep_OBJECTS) $(grep_DEPENDENCIES) $(EXTRA_grep_DEPENDENCIES) 
         @rm -f grep$(EXEEXT)
 -       $(AM_V_CCLD)$(LINK) $(grep_OBJECTS) $(grep_LDADD) $(LIBS)
 +       $(AM_V_CCLD)$(LINK) $(grep_OBJECTS) $(grep_LDADD) -Wl,--undefined=PSUserMainGet -lcli_main -lnacl_spawn -lppapi_simple -lnacl_io -lppapi -pthread $(LIBS)
  install-binSCRIPTS: $(bin_SCRIPTS)
         @$(NORMAL_INSTALL)
         @list='$(bin_SCRIPTS)'; test -n "$(bindir)" || list=; \
-diff --git a/src/grep.c b/src/grep.c
---- a/src/grep.c
-+++ b/src/grep.c
-@@ -2107,7 +2107,7 @@ fgrep_to_grep_pattern (size_t len, char const *keys,
- }
- 
- int
--main (int argc, char **argv)
-+nacl_main (int argc, char **argv)
- {
-   char *keys;
-   size_t keycc, oldcc, keyalloc;