Add specs for rb_eval_string

Author: andrykonchin

spec/ruby/optional/capi/kernel_spec.rb

@@ -503,6 +503,11 @@ def proc_caller
     it "evaluates a string of ruby code" do
       @s.rb_eval_string("1+1").should == 2
     end
+
+    it "captures local variables when called within a method" do
+      a = 2
+      @s.rb_eval_string("a+1").should == 3
+    end
   end
 
   describe "rb_eval_cmd_kw" do

spec/tags/optional/capi/kernel_tags.txt

@@ -1,2 +1,3 @@
 fails:C-API Kernel function rb_block_lambda converts the implicit block into a lambda
 slow:C-API Kernel function rb_set_end_proc runs a C function on shutdown
+fails:C-API Kernel function rb_eval_string captures local variables when called within a method