ci: add lists of expected failures & skipped tests for RAVEN with ACO
aco: remove unecessary p_split_vector with v2b reg class
ci: remove unused .test-radv-fossilize rule
ci: run radv-fossils with Pitcairn (GFX6) and Bonaire (GFX7) too
ci: set ACO_DEBUG=validateir,validatera global for RADV testing
radv: remove the LLVM version string when ACO is used
radv: do not print the LLVM version string twice in hang reports
radv: report correct backend IR in hang reports when ACO is used