re PR sanitizer/80403 (UBSAN: compile time crash with "type mismatch in binary expression" message in / and % expr)

	PR sanitizer/80403
	* fold-const.c (fold_ternary_loc): Revert
	use op0 instead of fold_convert_loc (loc, type, arg0) part of
	2017-04-12 change.

	* g++.dg/ubsan/pr80403-2.C: New test.

From-SVN: r246917