`RubyVM::ISeq.of` accept ISeq.

* iseq.c (iseqw_s_of): return given object if the given object is
  a `RubyVM::InstructionSequence`. We can specify ISeq for
  `TracePoint#enable(target:)`.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66015 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

iseq.c

@@ -2320,17 +2320,26 @@ iseqw_s_of(VALUE klass, VALUE body)
     rb_secure(1);
 
     if (rb_obj_is_proc(body)) {
-	iseq = vm_proc_iseq(body);
+        iseq = vm_proc_iseq(body);
 
-	if (!rb_obj_is_iseq((VALUE)iseq)) {
-	    iseq = NULL;
-	}
+	if (rb_obj_is_iseq((VALUE)iseq)) {
+            return iseqw_new(iseq);
+        }
+        else {
+            return Qnil;
+        }
+    }
+    else if (rb_obj_is_method(body)) {
+        return iseqw_new(rb_method_iseq(body));
+    }
+    else if (RB_TYPE_P(body, T_DATA) &&
+             RTYPEDDATA_P(body) &&
+             RTYPEDDATA_TYPE(body) == &iseqw_data_type) {
+        return body;
     }
     else {
-	iseq = rb_method_iseq(body);
+        return Qnil;
     }
-
-    return iseq ? iseqw_new(iseq) : Qnil;
 }
 
 /*