add missing EXPR_ALIGNOF case, its always constant

[r18637]

diff --git a/ast.c b/ast.c
index 4cfa3db..4f4a13f 100644 (file)
--- a/ast.c
+++ b/ast.c
@@ -818,6 +818,7 @@ bool is_constant_expression(const expression_t *expression)
        case EXPR_FUNCTION:
        case EXPR_PRETTY_FUNCTION:
        case EXPR_OFFSETOF:
+       case EXPR_ALIGNOF:
                return true;
 
        case EXPR_BUILTIN_SYMBOL: