Some architectures or specific cores do not have support in upstream
gcc. Currently, they are individually listed as exclusions in the
toolchain choice.
This poses a maintainance burden, as the knowledge about what gcc
version supports what architecture is split across many places: the
toolchain choice, the gcc version choice, the external toolchains.
As a first step, add a blind option that architectures or individual
cores may select to indicate they lack support in our internal backend.
Actual use of the option will come in followup patches.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>