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.
+ length=18, type=0x01
>12010002ffffff40220e4000050301020301
+ length=9, type=0x02
>090251000403040506
\
+ length=8, type=0x0b
>080b000302030405
\
+ length=9, type=0x04
>090400000103040506
\
+ length=7, type=0x05
>07050001020304
/
+ length=9, type=0x04
>090401000103040506
\
+ length=7, type=0x05
>07050101020304
/
+ length=9, type=0x04
>090402000103040506
\
+ length=7, type=0x05
>07050201020304
/
/
+ length=9, type=0x04
>090403000103040506
\
+ length=7, type=0x05
>07050301020304
/
/