Freeze `Rational` and `Complex` objects

mrbgems/mruby-complex/src/complex.c

@@ -24,6 +24,7 @@ complex_new(mrb_state *mrb, mrb_float real, mrb_float imaginary)
   struct mrb_complex *p = complex_ptr(mrb, comp);
   p->real = real;
   p->imaginary = imaginary;
+  MRB_SET_FROZEN_FLAG(s);
 
   return comp;
 }

mrbgems/mruby-complex/test/complex.rb

@@ -126,3 +126,9 @@ assert 'Complex::to_i' do
     Complex(1, 2).to_i
   end
 end
+
+assert 'Complex#frozen?' do
+  assert_predicate(1i, :frozen?)
+  assert_predicate(Complex(2,3), :frozen?)
+  assert_predicate(4+5i, :frozen?)
+end

mrbgems/mruby-rational/src/rational.c

@@ -37,6 +37,7 @@ rational_new(mrb_state *mrb, mrb_int numerator, mrb_int denominator)
   struct mrb_rational *p = rational_ptr(rat);
   p->numerator = numerator;
   p->denominator = denominator;
+  MRB_SET_FROZEN_FLAG(s);
   return rat;
 }
 

mrbgems/mruby-rational/test/rational.rb

@@ -278,3 +278,9 @@ assert 'Rational#negative?' do
   assert_not_predicate(Rational(2,3), :negative?)
   assert_not_predicate(Rational(0), :negative?)
 end
+
+assert 'Rational#frozen?' do
+  assert_predicate(1r, :frozen?)
+  assert_predicate(Rational(2,3), :frozen?)
+  assert_predicate(4/5r, :frozen?)
+end