feat: Integer#times, Integer#upto, Integer#downto を定義

core/integer.rbs

@@ -64,4 +64,10 @@ class Integer < Object
   #
   # alias to_s inspect
   # alias self.to_s self.inspect
+
+  def times: () { (Integer i) -> void } -> self
+
+  def upto: (Integer max) { (Integer i) -> void } -> self
+
+  def downto: (Integer min) { (Integer i) -> void } -> self
 end

test/integer.rb

@@ -56,4 +56,10 @@
 123.clamp 0, 100
 123.clamp 0, 100.0
 
+123.times { |i| i }
+
+123.upto(456) { |i| i }
+
+456.downto(123) { |i| i }
+
 # rubocop:enable all