cc/gcc: fix cc symlink when executables have an extension

When building a cross-compiler for a host which depends
on file extensions the symlink for cc was not installed correctly

Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>
[Yann E. MORIN: style fixes, enhancements, code prettying]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from 214c64ba8b21db15f610eca886fb194a6675e40c)

 reporter_name="Julien DUSSER"

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

 reporter_comment="Soft-float for the 405 PowerPC"