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
_ZN8Debugger12DebuggerInfoEv @ 1 NONAME ; Debugger::DebuggerInfo()
_ZN8Debugger7InstallEP13DDebuggerInfo @ 2 NONAME ; Debugger::Install(DDebuggerInfo*)
_ZN8Debugger7VersionEv @ 3 NONAME ; Debugger::Version()