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
ConvertFromUnicodeL__11UnicodeConvR5TDes8RC7TDesC16 @ 1 NONAME R3UNUSED ; UnicodeConv::ConvertFromUnicodeL(TDes8 &, TDesC16 const &)
ConvertToUnicodeL__11UnicodeConvR6TDes16RC6TDesC8 @ 2 NONAME R3UNUSED ; UnicodeConv::ConvertToUnicodeL(TDes16 &, TDesC8 const &)
IsLegalShortNameCharacter__11UnicodeConvUi @ 3 NONAME R3UNUSED ; UnicodeConv::IsLegalShortNameCharacter(unsigned int)
ConvertFromUnicodeL__11UnicodeConvR5TDes8RC7TDesC16i @ 4 NONAME R3UNUSED ; UnicodeConv::ConvertFromUnicodeL(TDes8 &, TDesC16 const &, int)
ConvertToUnicodeL__11UnicodeConvR6TDes16RC6TDesC8i @ 5 NONAME R3UNUSED ; UnicodeConv::ConvertToUnicodeL(TDes16 &, TDesC8 const &, int)