Hi,

If we want to overwrite parts of this structure, we're going to need it
to be more malleable than it is presently.

Run through and remove const from each of the members, create a non-const
tuning structure we can modify, and set aarch64_tune_params to always
point to this new structure. Change the -mtune parsing code to take a
copy of the tuning structure in use rather than just taking the
reference from within the processor struct. Change all the current
users of aarch64_tune_params which no longer need to dereference a
pointer.

Checked on aarch64-none-linux-gnueabi with no issues.

OK?

Thanks,
James

---
2015-06-23  James Greenhalgh  <james.greenhalgh@arm.com>

	* config/aarch64/aarch64-protos.h (tune_params): Remove
	const from members.
	(aarch64_tune_params): Remove const, change to no longer be
	a pointer.
	* config/aarch64/aarch64.c (aarch64_tune_params): Remove const,
	change to no longer be a pointer, initialize to generic_tunings.
	(aarch64_min_divisions_for_recip_mul): Change dereference of
	aarch64_tune_params to member access.
	(aarch64_reassociation_width): Likewise.
	(aarch64_rtx_mult_cost): Likewise.
	(aarch64_address_cost): Likewise.
	(aarch64_branch_cost): Likewise.
	(aarch64_rtx_costs): Likewise.
	(aarch64_register_move_cost): Likewise.
	(aarch64_memory_move_cost): Likewise.
	(aarch64_sched_issue_rate): Likewise.
	(aarch64_builtin_vectorization_cost): Likewise.
	(aarch64_override_options): Take a copy of the selected tuning
	struct in to aarch64_tune_params, rather than just setting
	a pointer, change dereferences of aarch64_tune_params to member
	accesses.
	(aarch64_override_options_after_change): Change dereferences of
	aarch64_tune_params to member access.
	(aarch64_macro_fusion_p): Likewise.
	(aarch_macro_fusion_pair_p): Likewise.
	* config/aarch64/cortex-a57-fma-steering.c (gate): Likewise.