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/risc/test_register_value1.rb

@@ -5,8 +5,8 @@ module Risc
 
     def setup
       Parfait.boot!(Parfait.default_test_options)
-      @r0 = RegisterValue.new(:r0 , :Message)
-      @r1 = RegisterValue.new(:r1 , :Space)
+      @r0 = RegisterValue.new(:message , :Message)
+      @r1 = RegisterValue.new(:id_1234 , :Space)
       @compiler = Risc.test_compiler
     end
 
@@ -28,16 +28,16 @@ module Risc
       assert @r0.get_new_left(:caller , @compiler).extra.empty?
     end
     def test_get_new_left_0_reg
-      assert_equal :r1 , @r0.get_new_left(:caller , @compiler).symbol
+      assert_equal :"message.caller" , @r0.get_new_left(:caller , @compiler).symbol
     end
     def test_get_new_left_1
       assert_equal RegisterValue , @r0.get_new_left(:caller , @compiler).class
     end
     def test_get_new_left_1_reg
-      assert_equal :r1 , @r0.get_new_left(:caller , @compiler).symbol
+      assert_equal :"id_1234.classes" , @r1.get_new_left(:classes , @compiler).symbol
     end
     def test_get_left_uses_extra
-      @r1 = RegisterValue.new(:r1 , :Space , type_arguments: @r0.type)
+      @r1 = RegisterValue.new(:message , :Space , type_arguments: @r0.type)
       # works with nil as compiler, because extra is used
       assert_equal :Message , @r1.get_new_left(:arguments , nil).type.class_name
     end