re PR sanitizer/85213 (-fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402)

	PR sanitizer/85213
	* fold-const.c (twoval_comparison_p): Remove SAVE_P argument and don't
	look through SAVE_EXPRs with non-side-effects argument.  Adjust
	recursive calls.
	(fold_comparison): Adjust twoval_comparison_p caller, don't handle
	save_p here.

	* c-c++-common/ubsan/pr85213.c: New test.

From-SVN: r259167