re PR sanitizer/85029 (-fsanitize=undefined internal compiler error: in maybe_optimize_ubsan_ptr_ifn, at sanopt.c:493)

	PR sanitizer/85029
	* sanopt.c (maybe_optimize_ubsan_ptr_ifn): If DECL_REGISTER (base),
	just don't try to optimize it rather than assert it never happens.

	* g++.dg/ubsan/pr85029.C: New test.

From-SVN: r258794