binutils/binutils: rename function that build target libraries

Prepare for the incoming build/host/target frontends.

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

reporter_name="Julien DUSSER"

reporter_url="http://sourceware.org/ml/crossgcc/2008-10/msg00054.html"

reporter_comment="Soft-float for the 405 PowerPC"