[ECOS] For GCCv3: recommend -fno-builtin and remove -fvtable-gc

[Richard Shih-Ping Chan <cshihpin at dso dot org dot sg>]

Hi eCos team - I would like to make two suggestions for GCC3

[1] Make -fno-builtin a default command line option.

This is to prevent unwanted optimisations of builtin functions
at the default optimisation level of -g -O2. An example is
the optimisation of printf and the consequent introduction of
extra symbols like putchar and puts by GCCv3.
This doesn't always link as some installs supply printf but not
putchar/puts. An example is the target+template pc+redboot. 
At -O2 GCCv3 really seems to convert
some printf to putchar/puts statements.

This should have no untoward effect on GCC2.95.


[2] -fvtable-gc is no longer supported by GCCv3 but I'm not sure
what implications that has.

Cheers
Richard Chan <cshihpin@dso.org.sg>