Add infrastructure to use common config files for generated config files.

/trunk/config/libc/glibc-eglibc.in-common | 4 4 0 0 ++++
/trunk/config/config.mk | 4 4 0 0 ++++
/trunk/config/libc.in | 7 0 7 0 -------
3 files changed, 8 insertions(+), 7 deletions(-)

 # x86_64 specific options

 config ARCH_x86_64

     select ARCH_64

     select ARCH_SUPPORT_ARCH

     select ARCH_SUPPORT_CPU

     select ARCH_SUPPORT_TUNE

     help

       The x86_64 architecture, as defined by:

         http://www.amd.com/us-en/Processors/DevelopWithAMD/0,,30_2252_875_7044,00.html