When "#pragma GCC visibility push" is used on builtin functions, it may
not be properly handled if "#pragma GCC visibility pop" is missing.
There is a testcase in gcc PR.
Visibility stuff should be fixed in current redhat/gcc-4_1-branch where the
visibility fixes from the trunk have been backported.
This will show up in FC6/RHEL5, for RHEL4 that's too invasive.