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)

# Bare metal config options

config KERNEL_bare_metal

    select BARE_METAL

    help

      'Bare metal' refers to those programs that run without any kernel.

      You probably want to say 'y' here if you plan to use your compiler

      to build bootloaders. It is not yet suitable to build Linux kernels,

      though, because the APCI stuff relies on the target C library headers

      being available?!?!...