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
_Z8Export01v @ 1 NONAME ; Export01()
_Z8Export02v @ 2 NONAME ; Export02()
_Z8Export03v @ 3 NONAME ; Export03()
_Z8Export04v @ 4 NONAME ; Export04()
_Z8Export05v @ 5 NONAME ; Export05()
_Z8Export06v @ 6 NONAME ; Export06()
_Z8Export07v @ 7 NONAME ; Export07()
_Z8Export08v @ 8 NONAME ; Export08()
_Z8Export09v @ 9 NONAME ; Export09()
_Z8Export10v @ 10 NONAME ; Export10()
_Z8Export11v @ 11 NONAME ; Export11()
_Z8Export12v @ 12 NONAME ; Export12()
_Z8Export13v @ 13 NONAME ; Export13()
_Z8Export14v @ 14 NONAME ; Export14()
_Z8Export15v @ 15 NONAME ; Export15()
_Z8Export16v @ 16 NONAME ; Export16()
_Z8Export17v @ 17 NONAME ; Export17()
_Z8Export18v @ 18 NONAME ; Export18()
_Z8Export19v @ 19 NONAME ; Export19()