Add Range#overlap?

core/src/main/ruby/jruby/kernel/range.rb

@@ -246,4 +246,26 @@ def self.cond_error(v)
     end
   end
   private_constant :BSearch
+
+  def overlap?(other)
+    raise TypeError, "wrong argument type #{other.class} (expected Range)" unless other.is_a?(Range)
+
+    selfEnd = self.end
+    selfBegin = self.begin
+    selfExclude = exclude_end?
+    otherBegin = other.begin
+    otherEnd = other.end
+    otherExclude = other.exclude_end?
+
+    !!(__overlap(otherBegin, selfEnd, selfExclude) &&
+      __overlap(selfBegin, otherEnd, otherExclude) &&
+      __overlap(selfBegin, selfEnd, selfExclude) &&
+      __overlap(otherBegin, otherEnd, otherExclude))
+  end
+
+  private def __overlap(from, to, excl)
+    less = (from || -Float::INFINITY) <=> (to || Float::INFINITY)
+    less = +1 if less == 0 && excl
+    less && less <= 0
+  end
 end