Ensure that the Xen build system variables EXTRA_CFLAGS_XEN_CORE and
EXTRA_CFLAGS_XEN_TOOLS are passed into the compile steps.
Update the hypervisor compilation to avoid passing in most compile flags
from the build environment via EXTRA_CFLAGS_XEN_CORE -- prefer the
compiler defaults and the flags set by the Xen build system, so only the
debug prefix flags are provided.
Observeration derived from the prior commit e99974aa, so:
Reported-by: Diego Sueiro <diego.sueiro@arm.com>
Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>