Predefined macro incompatibility (gcc vs egcs)

[Jim Wilson]

	Note, in particular, that "__i386" is defined by gcc, but not by egcs.

I believe this is fixed in egcs 1.0.2 as a side effect of another bug fix
(to fix the cpp doesn't define i386 problem).

This is a bug with the handling of -D options in CPP_SPEC, which aren't
treated exactly the same as -D options in CPP_PREDEFINES.  I wrote a note
to myself about it, and will fix it when I find the time if someone else
doesn't get to it first.

Jim