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/file/pipe_spec.rb

@@ -0,0 +1,32 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../../../shared/file/pipe', __FILE__)
+
+describe "File.pipe?" do
+  it_behaves_like :file_pipe, :pipe?, File
+end
+
+describe "File.pipe?" do
+  it "returns false if file does not exist" do
+    File.pipe?("I_am_a_bogus_file").should == false
+  end
+
+  it "returns false if the file is not a pipe" do
+    filename = tmp("i_exist")
+    touch(filename)
+
+    File.pipe?(filename).should == false
+
+    rm_r filename
+  end
+
+  platform_is_not :windows do
+    it "returns true if the file is a pipe" do
+      filename = tmp("i_am_a_pipe")
+      system "mkfifo #{filename}"
+
+      File.pipe?(filename).should == true
+
+      rm_r filename
+    end
+  end
+end