this shouldn't have been backported

configure.in

@@ -189,21 +189,6 @@ case $host_cpu in
     ;;
 esac
 
-dnl activate some gcc specific optimizations for gcc >= 4
-if test "$GCC" = "yes"; then
-  case $host_alias in
-  *darwin*)
-    GCC_MAJOR_VERSION=`$CC -dumpversion | /usr/bin/sed -nE '1s/([[0-9]]+)\.[[0-9]]+\..*/\1/;1p'`
-    ;;
-  *)
-    GCC_MAJOR_VERSION=`$CC --version | $SED -n '1s/[[^0-9]]*//;1s/\..*//;1p'`
-    ;;
-  esac
-  if test $GCC_MAJOR_VERSION -ge 4; then
-    CFLAGS="$CFLAGS -fvisibility=hidden"
-  fi
-fi
-
 case $host_alias in
   *solaris*)
     CPPFLAGS="$CPPFLAGS -D_POSIX_PTHREAD_SEMANTICS"