update Darwin install

[Rebecca Bendick]

I saw that other people had solved the same problem by installing  
Xcode 2.2, so I reinstalled that, but still get the same errror:

/usr/bin/ld: Undefined symbols:
_fprintf$LDBLStub
collect2: ld returned 1 exit status
make[2]: *** [genmodes] Error 1
make[1]: *** [stage2_build] Error 2
make: *** [bootstrap] Error 2


Help!!  I've been trying to sort this out on and off for months.