Put #object_id/#__id__/#id specs in the right place

1.8 defines Object#object_id, Object#__id__, and Object#id.
1.9 defines BasicObject#__id__ and Object#object_id.

These methods aren't defined on Kernel, they shouldn't be
in the kernel subdirectory.

core/basicobject/__id__spec.rb

@@ -0,0 +1,9 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../../../shared/object/object_id', __FILE__)
+
+ruby_version_is "1.9" do
+  describe "BasicObject#__id__" do
+    it_behaves_like :basic_object_id, :__id__, BasicObject
+    it_behaves_like :object_id,       :__id__, Object
+  end
+end

core/object/__id__spec.rb

@@ -0,0 +1,9 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../../../shared/object/object_id', __FILE__)
+
+ruby_version_is "".."1.9" do
+  describe "Object#__id__" do
+    it_behaves_like :basic_object_id, :__id__, Object
+    it_behaves_like :object_id,       :__id__, Object
+  end
+end

core/object/id_spec.rb

@@ -0,0 +1,9 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../../../shared/object/object_id', __FILE__)
+
+ruby_version_is "".."1.9" do
+  describe "Object#id" do
+    it_behaves_like :basic_object_id, :id, Object
+    it_behaves_like :object_id,       :id, Object
+  end
+end

core/object/object_id_spec.rb

@@ -0,0 +1,7 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../../../shared/object/object_id', __FILE__)
+
+describe "Object#object_id" do
+  it_behaves_like :basic_object_id, :object_id, Object
+  it_behaves_like :object_id,       :object_id, Object
+end

core/kernel/shared/object_id.rb → shared/object/object_id.rb

@@ -1,22 +1,24 @@
-describe :kernel_object_id, :shared => true do
-  # #object_id and #__id__ are aliases, so we only need one function
-  # that tests both methods
+# These examples hold for both BasicObject#__id__ and Object#object_id.
+describe :basic_object_id, :shared => true do
   it "returns an integer" do
-    mock('fixnum').send(@method).should be_kind_of(Integer)
-    nil.send(@method).should be_kind_of(Integer)
+    o1 = @object.new
+    o1.__send__(@method).should be_kind_of(Integer)
   end
 
   it "returns the same value on all calls to id for a given object" do
-    o1 = mock('x')
-    o1.send(@method).should == o1.send(@method)
+    o1 = @object.new
+    o1.__send__(@method).should == o1.send(@method)
   end
 
   it "returns different values for different objects" do
-    o1 = mock('o1')
-    o2 = mock('o2')
-    o1.send(@method).should_not == o2.send(@method)
+    o1 = @object.new
+    o2 = @object.new
+    o1.__send__(@method).should_not == o2.__send__(@method)
   end
+end
 
+# These examples hold for Object#object_id, or for specific subclasses.
+describe :object_id, :shared => true do
   it "returns the same value for two Fixnums with the same value" do
     o1 = 1
     o2 = 1