re PR sanitizer/81094 (-fsanitize=object-size does not instrument aggregate call arguments)

	PR sanitizer/81094
	* ubsan.c (instrument_null): Add T argument, use it instead
	of computing it based on IS_LHS.
	(instrument_object_size): Likewise.
	(pass_ubsan::execute): Adjust instrument_null and
	instrument_object_size callers to pass gimple_get_lhs or
	gimple_assign_rhs1 result to it.  Use instrument_null instead of
	calling get_base_address and instrument_mem_ref.  Handle
	aggregate call arguments for object-size sanitization.

	* c-c++-common/ubsan/object-size-11.c: New test.

From-SVN: r249239