pass return integer back out through exit

for testing of binaries later (and off course general correctness)
Some tests were using the fact that the interpreter was used, changed those to return ints rather than strings

test/risc/interpreter/assign/test_assign_thrice.rb

@@ -35,8 +35,9 @@ module Risc
              FunctionReturn, SlotToReg, SlotToReg, RegToSlot, Branch,
              SlotToReg, SlotToReg, RegToSlot, SlotToReg, SlotToReg,
              RegToSlot, SlotToReg, SlotToReg, SlotToReg, FunctionReturn,
-             Transfer, Syscall, NilClass]
-      assert_equal 15 , get_return.value
+             SlotToReg, SlotToReg, Branch, Transfer, Syscall,
+             NilClass]
+      assert_equal 15 , get_return
     end
 
   end