gcc-4.6: Add fix for relocation problem and ccache
If the toolchain is reused from sstate and ccache is installed, build failures
were occuring due to gcc trying to access the original sysroot rather than the
new one, particularly if the old sysroot existed but was not readable by the
current user.
This turns out of the an issue inside gcc to do with preservation of the sysroot
option. See the gcc patch for more details. It only triggers when preprocessed
sources are used which happens when ccache is used.
The same issue occurs with c++ and c++-cpp-output so the same fix is applied there.
[YOCTO #2074]
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
