Use mmap instead of exec mem for Selinux machines. Fixes crash on Fedora.

configure

@@ -130,6 +130,8 @@ for opt do
   ;;
   --with-libgcc) use_libgcc="yes"
   ;;
+  --with-selinux) have_selinux="yes"
+  ;;
   --help|-h) show_help="yes"
   ;;
   esac
@@ -229,7 +231,8 @@ echo "  --cross-prefix=PREFIX    use PREFIX for compile tools [$cross_prefix]"
 echo "  --sysroot=PREFIX         prepend PREFIX to library/include paths []"
 echo "  --cc=CC                  use C compiler CC [$cc]"
 echo "  --with-libgcc            use /lib/libgcc_s.so.1 instead of libtcc1.a"
-echo ""
+echo "  --with-selinux           use mmap instead of exec mem"
+echo "                           [requires write access to /tmp]"echo ""
 #echo "NOTE: The object files are build at the place where configure is launched"
 exit 1
 fi
@@ -357,6 +360,10 @@ if test "$use_libgcc" = "yes" ; then
   echo "#define CONFIG_USE_LIBGCC" >> $TMPH
   echo "CONFIG_USE_LIBGCC=yes" >> config.mak
 fi
+if test "$have_selinux" = "yes" ; then
+  echo "#define HAVE_SELINUX" >> $TMPH
+  echo "HAVE_SELINUX=yes" >> config.mak
+fi
 version=`head $source_path/VERSION`
 echo "VERSION=$version" >>config.mak
 echo "#define TCC_VERSION \"$version\"" >> $TMPH