PR middle-end/83373 - False positive reported by -Wstringop-overflow

PR middle-end/83373 - False positive reported by -Wstringop-overflow

PR middle-end/83373 - False positive reported by -Wstringop-overflow
PR tree-optimization/78450 - strlen(s) return value can be assumed to be less than the size of s

gcc/ChangeLog:

	PR middle-end/83373
	PR tree-optimization/78450
	* tree-ssa-strlen.c (maybe_set_strlen_range): New function.
	(handle_builtin_strlen): Call it.

gcc/testsuite/ChangeLog:

	PR middle-end/83373
	PR tree-optimization/78450
	* gcc.dg/pr83373.c: New test.
	* gcc.dg/strlenopt-36.c: New test.
	* gcc.dg/strlenopt-37.c: New test.

From-SVN: r255790