gcc/ChangeLog:

	PR tree-optimization/83603
	* calls.c (maybe_warn_nonstring_arg): Avoid accessing function
	arguments past the endof the argument list in functions declared
	without a prototype.
	* gimple-ssa-warn-restrict.c (wrestrict_dom_walker::check_call):
	Avoid checking when arguments are null.

gcc/testsuite/ChangeLog:

	PR tree-optimization/83603
	* gcc.dg/Wrestrict-4.c: New test.

From-SVN: r256217