re PR bootstrap/78817 (stage2 bootstrap failure in vec.h:1613:5: error: argument 1 null where non-null expected after r243661)

	PR bootstrap/78817
	* tree-pass.h (make_pass_post_ipa_warn): Declare.
	* builtins.c (validate_arglist): Adjust get_nonnull_args call.
	Check for NULL pointer argument to nonnull arg here.
	(validate_arg): Revert 2016-12-14 changes.
	* calls.h (get_nonnull_args): Remove declaration.
	* tree-ssa-ccp.c: Include diagnostic-core.h.
	(pass_data_post_ipa_warn): New variable.
	(pass_post_ipa_warn): New class.
	(pass_post_ipa_warn::execute): New method.
	(make_pass_post_ipa_warn): New function.
	* tree.h (get_nonnull_args): Declare.
	* tree.c (get_nonnull_args): New function.
	* calls.c (maybe_warn_null_arg): Removed.
	(maybe_warn_null_arg): Removed.
	(initialize_argument_information): Revert 2016-12-14 changes.
	* passes.def: Add pass_post_ipa_warn after first ccp after IPA.
c-family/
	* c-common.c (struct nonnull_arg_ctx): New type.
	(check_function_nonnull): Return bool instead of void.  Use
	nonnull_arg_ctx as context rather than just location_t.
	(check_nonnull_arg): Adjust for the new context type, set
	warned_p to true if a warning has been diagnosed.
	(check_function_arguments): Return bool instead of void.
	* c-common.h (check_function_arguments): Adjust prototype.
c/
	* c-typeck.c (build_function_call_vec): If check_function_arguments
	returns true, set TREE_NO_WARNING on CALL_EXPR.
cp/
	* typeck.c (cp_build_function_call_vec): If check_function_arguments
	returns true, set TREE_NO_WARNING on CALL_EXPR.
	* call.c (build_over_call): Likewise.

From-SVN: r243874