PR tree-optimization/91567 - Spurious -Wformat-overflow warnings building glibc ...

PR tree-optimization/91567 - Spurious -Wformat-overflow warnings building glibc (32-bit only)

gcc/ChangeLog:

	PR tree-optimization/91567
	* gimple-ssa-sprintf.c (get_string_length): Handle more forms of lengths
	of unknown strings.
	* vr-values.c (vr_values::extract_range_basic): Set strlen upper bound
	to PTRDIFF_MAX - 2.

gcc/testsuite/ChangeLog:

	PR tree-optimization/91567
	* gcc.dg/tree-ssa/builtin-snprintf-6.c: Xfail a subset of assertions
	on targets other than x86_64 to work around PR 83543.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-22.c: New test.

From-SVN: r274976