Add -rdynamic
Added very basic atomic and sync functions
Disable struct alignment
or1k is supported for fPIC in libiberty
or1k: Re-worked TLS handling to register correctly

A problem was detected where the call to __tls_get_addr would be emitted
but the call-clobbered registers wouldn't register as clobbered.

These changes makes GCC take TLS in account in the earlier phases and
seems to do the correct thing.