patch 9.0.1188: return value of type() for class and object unclear

Problem:    Return value of type() for class and object unclear.
Solution:   Add v:t_object and v:t_class.
diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index ea3ce61..f202da0 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -9947,6 +9947,8 @@
 			Job:	    8  |v:t_job|
 			Channel:    9  |v:t_channel|
 			Blob:	   10  |v:t_blob|
+			Class	   12  |v:t_class|
+			Object	   13  |v:t_object|
 		For backward compatibility, this method can be used: >
 			:if type(myvar) == type(0)
 			:if type(myvar) == type("")