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
Export1__Fv @ 1 NONAME ; Export1(void)
Export2__Fv @ 2 NONAME ; Export2(void)
Export3__Fv @ 3 NONAME ; Export3(void)
Export4__Fv @ 4 NONAME ABSENT ; Export4(void)
Export5__Fi @ 5 NONAME ; Export5(int)