kvm: extboot: fix -fno-stack-protector usage
Option -fno-stack-protector breaks kvm-userspace in environments without
stack-protector functionality. They fail with "unrecognized command line
option" when compiling extboot.
This patch removes the fix -fno-stack-protector option and replaces it
with a detection that only adds -fno-stack-protector if the option is
supported by the used gcc.
The detection code is copied from kernel sources scripts/Kbuild.include.
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>