Add specs for [Feature #13983] Rational and Complex should be frozen

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60505 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/ruby/core/kernel/frozen_spec.rb

@@ -49,4 +49,30 @@ describe "Kernel#frozen?" do
       @symbol.frozen?.should be_true
     end
   end
+
+  ruby_version_is "2.5" do
+    describe "on a Complex" do
+      it "returns true" do
+        c = Complex(1.3, 3.1)
+        c.frozen?.should be_true
+      end
+
+      it "literal returns true" do
+        c = eval "1.3i"
+        c.frozen?.should be_true
+      end
+    end
+
+    describe "on a Rational" do
+      it "returns true" do
+        r = Rational(1, 3)
+        r.frozen?.should be_true
+      end
+
+      it "literal returns true" do
+        r = eval "1/3r"
+        r.frozen?.should be_true
+      end
+    end
+  end
 end