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
_ZN31DSimulatedIicBusChannelSlaveI2cC1EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 5 NONAME
_ZN31DSimulatedIicBusChannelSlaveI2cC2EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 6 NONAME
_ZN32DSimulatedIicBusChannelMasterI2cC1EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 7 NONAME
_ZN32DSimulatedIicBusChannelMasterI2cC2EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexE @ 8 NONAME
_ZN37DSimulatedIicBusChannelMasterSlaveI2cC1EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexEP32DSimulatedIicBusChannelMasterI2cP31DSimulatedIicBusChannelSlaveI2c @ 9 NONAME
_ZN37DSimulatedIicBusChannelMasterSlaveI2cC2EN14DIicBusChannel8TBusTypeENS0_14TChannelDuplexEP32DSimulatedIicBusChannelMasterI2cP31DSimulatedIicBusChannelSlaveI2c @ 10 NONAME
_ZTI19DIicBusChannelSlave @ 11 NONAME
_ZTI20DIicBusChannelMaster @ 12 NONAME
_ZTI25DIicBusChannelMasterSlave @ 13 NONAME
_ZTI31DSimulatedIicBusChannelSlaveI2c @ 14 NONAME
_ZTI32DSimulatedIicBusChannelMasterI2c @ 15 NONAME
_ZTI37DSimulatedIicBusChannelMasterSlaveI2c @ 16 NONAME
_ZTV19DIicBusChannelSlave @ 17 NONAME
_ZTV20DIicBusChannelMaster @ 18 NONAME
_ZTV25DIicBusChannelMasterSlave @ 19 NONAME
_ZTV31DSimulatedIicBusChannelSlaveI2c @ 20 NONAME
_ZTV32DSimulatedIicBusChannelMasterI2c @ 21 NONAME
_ZTV37DSimulatedIicBusChannelMasterSlaveI2c @ 22 NONAME