COMPMID-920: Introduce prepare() stage

Change-Id: I08ddb7f6e061178e7566518b48e4e18f8f078596
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/129825
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
17 files changed