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
_Z19CreateLogicalDevicev @ 1 NONAME
_ZN5Debug13StopModeDebug7GetListEPKNS_9TListItemEi @ 2 NONAME
_ZN5Debug13StopModeDebug7TestAPIEPKNS_9TListItemE @ 3 NONAME
_ZN5Debug13StopModeDebug9ExitPointEi @ 4 NONAME
_ZTI11DDebugAgent @ 5 NONAME
_ZTI12DRMDStepping @ 6 NONAME
_ZTI14DBufferManager @ 7 NONAME
_ZTI14DTargetProcess @ 8 NONAME
_ZTI15DProcessTracker @ 9 NONAME
_ZTI16DRM_DebugChannel @ 10 NONAME
_ZTI17D_RMD_Breakpoints @ 11 NONAME
_ZTI21DRM_DebugEventHandler @ 12 NONAME
_ZTI22DRM_DebugDriverFactory @ 13 NONAME
_ZTV11DDebugAgent @ 14 NONAME
_ZTV12DRMDStepping @ 15 NONAME
_ZTV14DBufferManager @ 16 NONAME
_ZTV14DTargetProcess @ 17 NONAME
_ZTV15DProcessTracker @ 18 NONAME
_ZTV16DRM_DebugChannel @ 19 NONAME
_ZTV17D_RMD_Breakpoints @ 20 NONAME
_ZTV21DRM_DebugEventHandler @ 21 NONAME
_ZTV22DRM_DebugDriverFactory @ 22 NONAME