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
_ZN3UTF13TTraceContext16DefaultModuleUidEv @ 1 NONAME
_ZN3UTF16WouldBeTracedNowERKNS_13TTraceContextE @ 2 NONAME
_ZN3UTF5PrintERKNS_13TTraceContextERK6TDesC8 @ 3 NONAME
_ZN3UTF5PrintERKNS_13TTraceContextERK7TDesC16 @ 4 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEt @ 5 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEtPKvi @ 6 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEtRK6TDesC8 @ 7 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEtRK7TDesC16 @ 8 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEth @ 9 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEtm @ 10 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEtmm @ 11 NONAME
_ZN3UTF5TraceERKNS_13TTraceContextEtt @ 12 NONAME
_ZN3UTF6PrintfERKNS_13TTraceContextE11TRefByValueIK6TDesC8Ez @ 13 NONAME
_ZN3UTF6PrintfERKNS_13TTraceContextE11TRefByValueIK7TDesC16Ez @ 14 NONAME
_ZN3UTF6PrintfERKNS_13TTraceContextEPKcz @ 15 NONAME
_ZNK3UTF13TTraceContext14ClassificationEv @ 16 NONAME
_ZNK3UTF13TTraceContext17HasProgramCounterEv @ 17 NONAME
_ZNK3UTF13TTraceContext23HasThreadIdentificationEv @ 18 NONAME
_ZNK3UTF13TTraceContext9ModuleUidEv @ 19 NONAME