moving to SA register names (wip)

starting to implement register allocation by first creating SA
Single Assignment means a register is only every assigned a value once. Hence for any operation involving another register, a new register is created.
We do this with a naming scheme for the registers in dot notation (as it would be in c) which means 2 registers with the same name, should have the same contents. This does not apply to temporaries, but that is another day.
Starting WIP now, and will create many red commits before merging when green.

test/support/fake_compiler.rb

@@ -27,12 +27,14 @@ module Risc
     def resolve_type(name)
       Parfait.object_space.types.values.first
     end
-    def use_reg(type , extra = {})
-      RegisterValue.new(:r1 , type)
-    end
     def reset_regs
     end
     def add_constant(c)
     end
   end
+  class RegisterValue
+    def is_object?
+      @symbol.to_s.start_with?("id_")
+    end
+  end
 end