PR target/47237
	* cgraph.h (cgraph_local_info): New field can_change_signature.
	* ipa-cp.c (ipcp_update_callgraph): Only compute args_to_skip if callee
	signature can change.
	(ipcp_estimate_growth): Call sequence simplify only if calle signature
	can change.
	(ipcp_insert_stage): Only compute args_to_skip if signature can change.
	(cgraph_function_versioning): We can not change signature of functions
	that don't allow that.
	* lto-cgraph.c (lto_output_node): Stream local.can_change_signature.
	(lto_input_node): Likewise.
	* ipa-inline.c (compute_inline_parameters): Compute local.can_change_signature.
	* ipa-split.c (visit_bb): Never split away APPLY_ARGS.
	* tree-sra.c (ipa_sra_preliminary_function_checks): Give up on functions
	that can not change signature.
	* i386.c (ix86_function_regparm, ix86_function_sseregparm,
	init_cumulative_args): Do not use local calling conventions for functions
	that can not change signature.

From-SVN: r169290