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
?CreateLogicalDevice@@YAPAVDLogicalDevice@@XZ @ 1 NONAME ; class DLogicalDevice * __cdecl CreateLogicalDevice(void)
?ExportMultiplyFunction@@YAHII@Z @ 2 NONAME ; int __cdecl ExportMultiplyFunction(unsigned int,unsigned int)