Marshal.load: also freeze extended objects

[Bug #19427]

The `proc` wouldn't be called either, that fixes both.

marshal.c

@@ -1865,6 +1865,7 @@ r_object_for(struct load_arg *arg, bool partial, int *ivp, VALUE extmod, int typ
                     rb_extend_object(v, m);
                 }
             }
+            v = r_leave(v, arg, partial);
         }
         break;
 

spec/ruby/core/marshal/shared/load.rb

@@ -69,6 +69,18 @@
         Object.should_not.frozen?
       end
 
+      ruby_bug "#19427", ""..."3.3" do
+        it "does freeze extended objects" do
+          object = Marshal.load("\x04\be:\x0FEnumerableo:\vObject\x00", freeze: true)
+          object.should.frozen?
+        end
+
+        it "does freeze extended objects with instance variables" do
+          object = Marshal.load("\x04\be:\x0FEnumerableo:\vObject\x06:\n@ivarT", freeze: true)
+          object.should.frozen?
+        end
+      end
+
       describe "when called with a proc" do
         it "call the proc with frozen objects" do
           arr = []
@@ -132,6 +144,14 @@
       end
     end
 
+    ruby_bug "#19427", ""..."3.3" do
+      it "call the proc with extended objects" do
+        objs = []
+        obj = Marshal.load("\x04\be:\x0FEnumerableo:\vObject\x00", Proc.new { |o| objs << o; o })
+        objs.should == [obj]
+      end
+    end
+
     it "returns the value of the proc" do
       Marshal.send(@method, Marshal.dump([1,2]), proc { [3,4] }).should ==  [3,4]
     end