cpp only piece not parametrized with gcc-lib directory?

[Horst von Brand <vonbrand at sleipnir dot valparaiso dot cl>]

I built egcs-1.0.2 some days back for i586-pc-linux-gnu (the default), but
my compilers live in i386-redhat-linux, per RedHat-5.0 convention.  Not
wanting to rebuild everything, I just moved the directory egcs-2.90.27 from
/usr/lib/gcc-lib/i586-pc-linux-gnu to /usr/lib/gcc-lib/i386-redhat-linux. I
tried a small C program with:

      gcc -V egcs-2.90.27 -v hello.c

The _only_ (and easily fixed) trouble was that cpp hardwired
/usr/lib/gcc-lib/i586-pc-linux-gnu/include into the <> search path. It
would be nice if it got this, e.g., from either a -I created by the
compiler driver, or read it from .../specs.

Or am I totally off-base here?

Thanks for a excellent compiler!
-- 
Horst von Brand                             vonbrand@sleipnir.valparaiso.cl
Casilla 9G, Viņa del Mar, Chile                               +56 32 672616