frontend: add colours to conditional AST tree debug output

frontend/debug.c

@@ -143,6 +143,7 @@ extern enum ivy_status print_ast_node(
 	case IVY_AST_MSGH:
 	case IVY_AST_UNIT_PACKAGE:
 	case IVY_AST_UNIT_IMPORT:
+	case IVY_AST_COND_GROUP:
 		b_puts("[magenta]");
 		break;
 	case IVY_AST_OP:
@@ -155,6 +156,7 @@ extern enum ivy_status print_ast_node(
 	case IVY_AST_DOUBLE:
 		b_puts("[yellow]");
 		break;
+	case IVY_AST_COND:
 	case IVY_AST_BLOCK:
 		b_puts("[red]");
 		break;