make the interpreter platform

but still using the risc_instruction stream

lib/risc/interpreter_platform.rb

@@ -0,0 +1,38 @@
+
+module Risc
+  class InterpreterPlatform
+    def translator
+      IdentityTranslator.new
+    end
+    def loaded_at
+      0x90
+    end
+    def padding
+      0x100 - loaded_at
+    end
+  end
+  class Instruction
+    def nil_next
+      @next = nil
+    end
+    def byte_length
+      4
+    end
+    def assemble(io)
+      io.write_unsigned_int_32(self)
+    end
+    class Branch < Instruction
+      def first
+        self
+      end
+    end
+  end
+  class IdentityTranslator
+    def translate(code)
+      return Label.new( code.source , code.name ) if code.is_a?(Label)
+      ret = code.dup
+      ret.nil_next
+      ret
+    end
+  end
+end