cc/gcc: always build core compilers to run on the build machine

The core compilers are used to build the C library, so they
should always run on the build machine, not on the host.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 reporter_name="Alexander BIGGA"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-06/msg00031.html"

 reporter_comment=""