Fix warnings

ir/be/amd64/amd64_new_nodes.c

@@ -109,6 +109,7 @@ static const char *get_insn_mode_string(amd64_insn_mode_t mode)
 	case INSN_MODE_16:  return "16";
 	case INSN_MODE_32:  return "32";
 	case INSN_MODE_64:  return "64";
+	case INSN_MODE_80:  return "80";
 	case INSN_MODE_128: return "128";
 	case INSN_MODE_INVALID: break;
 	}

ir/be/amd64/bearch_amd64.c

@@ -64,6 +64,7 @@ static int get_insn_mode_bytes(amd64_insn_mode_t insn_mode)
 	case INSN_MODE_32:      return 4;
 	case INSN_MODE_64:      return 8;
 	case INSN_MODE_128:     return 16;
+	case INSN_MODE_80:
 	case INSN_MODE_INVALID: break;
 	}
 	panic("bad insn mode");