Switch to add/remove instruction mutation

gen/instruction.go

@@ -2,13 +2,13 @@ package gen
 
 import "github.com/firestuff/subcoding/vm"
 
-func randInstruction(prog *vm.Program) *vm.Instruction {
+func RandInstruction(prog *vm.Program) *vm.Instruction {
 	instr := &vm.Instruction{
-		OpCode: randOpCode(),
+		OpCode: RandOpCode(),
 	}
 
 	for i, t := range vm.OperandsByOpCode[instr.OpCode] {
-		instr.Operands[i] = randOperand(prog, t)
+		instr.Operands[i] = RandOperand(prog, t)
 	}
 
 	return instr