Determine access types in ipa-icf-gimple.c

Determine access types in ipa-icf-gimple.c

This patch adds logic to determine access type (normal or memory) for every
operand.  This makes it possible to compare memory accesses more carefully
which will be implemented in a followup patch.

	* ipa-icf-gimple.c: Include gimple-walk.h.
	(func_checker::compare_ssa_name): Update call of compare_operand.
	(func_checker::hash_operand): Fix comment and add variant taking
	operand_access_type parameter.
	(func_checker::compare_operand): Add operand_access_type parameter.
	(func_checker::compare_asm_inputs_outputs): Add
	operand_access_type_map parameter; update use of
	func_checker::compare_operand.
	(func_checker::compare_gimple_call): Update use of
	func_checker::compare_operand.
	(func_checker::compare_gimple_assign): Likewise.
	(func_checker::compare_gimple_cond): Likewise.
	(func_checker::compare_gimple_switch): Likewise.
	(func_checker::compare_gimple_return): Likewise.
	(func_checker::compare_gimple_goto): Likewise.
	(func_checker::compare_gimple_asm): Likewise.
	(visit_load_store): New static functio.
	(func_checker::classify_operands): New member function.
	(func_checker::get_operand_access_type): New member function.
	* ipa-icf-gimple.h (func_checker::operand_access_type): New enum
	(func_checker::operand_access_type_map): New typedef.
	(func_checker::compare_operand): Update prototype.
	(func_checker::compare_asm_inputs_outputs): Likewise.
	(func_checker::cleassify_operands): Declare.
	(func_checker::get_operand_access_type): Declare.
	(func_checker::hash_operand): New variant with operand_access_type.
	* ipa-icf.c (sem_function::hash_stmt): Update uses of hash_operand.
	(sem_function::compare_phi_node): Update use of compare_operand.