re PR tree-optimization/67921 ("internal compiler error: in build_polynomial_chrec, at tree-chrec.h:147" when using -fsanitize=undefined)


	PR tree-optimization/67921
	* fold-const.c (split_tree): New parameters.  Convert pointer
	type variable part to proper type before negating. 
	(fold_binary_loc): Pass new arguments to split_tree.

	gcc/testsuite/ChangeLog
	PR tree-optimization/67921
	* c-c++-common/ubsan/pr67921.c: New test.

From-SVN: r233042