Sometimes when a test doesn't work it's convenient to run it through GDB. This patch adds a variable you can set on the make commandline to conveniently enable all the compiler flags needed to make that work. Change-Id: I3ac80ad095e0b72cc3176cbf915d1f390cd01558 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://review.coreboot.org/c/coreboot/+/81112 Reviewed-by: Jakub Czapiga <czapiga@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Yu-Ping Wu <yupingso@google.com>