c++: dump-lang-raw with obj_type_ref fields

Raw dump of lang tree was missing information about virtual method call.
The information is provided in "tok" field of obj_type_ref.

gcc/ChangeLog:

	* tree-dump.cc (dequeue_and_dump): Handle OBJ_TYPE_REF.

gcc/testsuite/ChangeLog:

	* g++.dg/diagnostic/lang-dump-1.C: New test.