Ignoring raise double() specs for ruby 1.9.2

This ignores specs that check for the removal of
`to_str` from Ruby 1.9.2 as they won't work there
due to the Ruby runtime calling `to_str` on a double
without checking if the double implements `to_str`.

lib/rspec/mocks/test_double.rb

@@ -53,8 +53,6 @@ def to_s
         inspect.gsub('<','[').gsub('>',']')
       end
 
-      #alias_method :to_str, :to_s
-
       # @private
       def respond_to?(message, incl_private=false)
         __mock_proxy.null_object? ? true : super

spec/rspec/mocks/double_spec.rb

@@ -773,7 +773,7 @@ def add_call
         end
       end
 
-      describe "#to_str" do
+      describe "#to_str", :unless => RUBY_VERSION == '1.9.2' do
         it "should not respond to #to_str to avoid being coerced to strings by the runtime" do
           double = double("Foo")
           expect { double.to_str }.to raise_error(

spec/rspec/mocks/verifying_double_spec.rb

@@ -467,7 +467,7 @@ module Mocks
           }.to raise_error(/Module or String expected/)
         end
 
-        it "trying to raise a class_double raises a TypeError" do
+        it "trying to raise a class_double raises a TypeError", :unless => RUBY_VERSION == '1.9.2' do
           subject = Object.new
           class_double("StubbedError").as_stubbed_const
           allow(subject).to receive(:some_method).and_raise(StubbedError)