Enhance the base/rom extension to generate the symbol file of the rom built.
The symbol file is placed in epoc32/rom/<baseport_name>, along with the rom log and final oby file.
EXPORTS
_Z20CreatePhysicalDevicev @ 1 NONAME
_ZN20TIicBusSlaveCallback7DfcFuncEPv @ 2 NONAME
_ZN25DIicBusChannelMasterSlaveC1EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexEP20DIicBusChannelMasterP19DIicBusChannelSlave @ 3 NONAME
_ZN25DIicBusChannelMasterSlaveC2EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexEP20DIicBusChannelMasterP19DIicBusChannelSlave @ 4 NONAME
_ZN31DSimulatedIicBusChannelSlaveSpiC1EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 5 NONAME
_ZN31DSimulatedIicBusChannelSlaveSpiC2EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 6 NONAME
_ZN32DSimulatedIicBusChannelMasterSpiC1EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 7 NONAME
_ZN32DSimulatedIicBusChannelMasterSpiC2EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 8 NONAME
_ZTI19DIicBusChannelSlave @ 9 NONAME
_ZTI20DIicBusChannelMaster @ 10 NONAME
_ZTI25DIicBusChannelMasterSlave @ 11 NONAME
_ZTI31DSimulatedIicBusChannelSlaveSpi @ 12 NONAME
_ZTI32DSimulatedIicBusChannelMasterSpi @ 13 NONAME
_ZTV19DIicBusChannelSlave @ 14 NONAME
_ZTV20DIicBusChannelMaster @ 15 NONAME
_ZTV25DIicBusChannelMasterSlave @ 16 NONAME
_ZTV31DSimulatedIicBusChannelSlaveSpi @ 17 NONAME
_ZTV32DSimulatedIicBusChannelMasterSpi @ 18 NONAME