[AArch64] Enable autoprefetcher modelling in the scheduler
* config/aarch64/aarch64-protos.h
(struct tune_params): Add autoprefetcher_model field.
* config/aarch64/aarch64.c: Include params.h
(generic_tunings): Specify autoprefetcher_model value.
(cortexa53_tunings): Likewise.
(cortexa57_tunings): Likewise.
(cortexa72_tunings): Likewise.
(thunderx_tunings): Likewise.
(xgene1_tunings): Likewise.
(aarch64_first_cycle_multipass_dfa_lookahead_guard): New function.
(TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD): Define.
(aarch64_override_options_internal): Set
PARAM_SCHED_AUTOPREF_QUEUE_DEPTH param.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@229412 138bc75d-0d04-0410-961f-82ee72b054a4