Finalize method matching

* Add tests for all edge cases I could create
* Add infrastructure for loading mutations into the vm.
* The fun part is next!

tasks/metrics/heckle.rake

@@ -34,6 +34,7 @@ begin
       raise "ruby2ruby version #{Ruby2Ruby::VERSION} may not work properly, 1.2.2 *only* is recommended for use with heckle"
     end
 
+    require File.expand_path('../../../spec/support/fake_ast',__FILE__)
     require 'mutant'
 
     root_module_regexp = Regexp.union('Mutant')
@@ -54,6 +55,13 @@ begin
     ObjectSpace.each_object(Module) do |mod|
       next unless mod.name =~ /\A#{root_module_regexp}(?::|\z)/
 
+      # Mutation::Loader is to rbx specific
+      next if mod == Mutant::Loader
+      # Mutation::Matcher::Method is to rbx specific
+      next if mod == Mutant::Matcher::Method
+      # Mutation::Context::Constant is to rbx specific
+      next if mod == Mutant::Context::Constant
+
       spec_prefix = spec_dir.join(mod.name.underscore)
 
       specs = []