X11Dependency objects: fix hash equality

Library/Homebrew/requirements/x11_dependency.rb

@@ -34,4 +34,8 @@ class X11Dependency < Requirement
     return unless X11Dependency === other
     min_version <=> other.min_version
   end
+
+  def eql?(other)
+    super && min_version == other.min_version
+  end
 end

Library/Homebrew/test/test_x11_dependency.rb

@@ -19,6 +19,13 @@ class X11DependencyTests < Homebrew::TestCase
     assert !y.eql?(x)
   end
 
+  def test_different_min_version
+    x = X11Dependency.new
+    y = X11Dependency.new("x11", %w[2.5])
+    refute x.eql?(y)
+    refute y.eql?(x)
+  end
+
   def test_x_env
     x = X11Dependency.new
     x.stubs(:satisfied?).returns(true)