move all arm instructions to own folder and fold inheritance

lib/arm/instruction.rb

@@ -0,0 +1,27 @@
+module Arm
+  # The arm machine has following instruction classes
+  # - Memory
+  # - Stack
+  # - Logic
+  # - Math
+  # - Control/Compare
+  # - Move
+  # - Call  class Instruction
+  class Instruction
+    def initialize  options
+      @attributes = options
+    end
+    attr_reader :attributes
+    def opcode
+      @attributes[:opcode]
+    end
+  end
+end
+
+require_relative "constants"
+require_relative "instructions/call_instruction"
+require_relative "instructions/compare_instruction"
+require_relative "instructions/logic_instruction"
+require_relative "instructions/memory_instruction"
+require_relative "instructions/move_instruction"
+require_relative "instructions/stack_instruction"