Add in-tree mspec and ruby/spec

* For easier modifications of ruby/spec by MRI developers.
* .gitignore: track changes under spec.
* spec/mspec, spec/rubyspec: add in-tree mspec and ruby/spec.
  These files can therefore be updated like any other file in MRI.
  Instructions are provided in spec/README.
  [Feature #13156] [ruby-core:79246]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/rubyspec/core/array/include_spec.rb

@@ -0,0 +1,33 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Array#include?" do
+  it "returns true if object is present, false otherwise" do
+    [1, 2, "a", "b"].include?("c").should == false
+    [1, 2, "a", "b"].include?("a").should == true
+  end
+
+  it "determines presence by using element == obj" do
+    o = mock('')
+
+    [1, 2, "a", "b"].include?(o).should == false
+
+    def o.==(other); other == 'a'; end
+
+    [1, 2, o, "b"].include?('a').should == true
+
+    [1, 2.0, 3].include?(2).should == true
+  end
+
+  it "calls == on elements from left to right until success" do
+    key = "x"
+    one = mock('one')
+    two = mock('two')
+    three = mock('three')
+    one.should_receive(:==).any_number_of_times.and_return(false)
+    two.should_receive(:==).any_number_of_times.and_return(true)
+    three.should_not_receive(:==)
+    ary = [one, two, three]
+    ary.include?(key).should == true
+  end
+end