ast: add str for ArrayInit (#8022)

vlib/v/ast/str.v

@@ -183,6 +183,23 @@ pub fn (lit &StringInterLiteral) get_fspec_braces(i int) (string, bool) {
 // string representation of expr
 pub fn (x Expr) str() string {
 	match x {
+		ArrayInit {
+			mut fields := []string{}
+			if x.has_len {
+				fields << 'len: $x.len_expr.str()'
+			}
+			if x.has_cap {
+				fields << 'cap: $x.cap_expr.str()'
+			}
+			if x.has_default {
+				fields << 'init: $x.default_expr.str()'
+			}
+			if fields.len > 0 {
+				return '[]T{${fields.join(', ')}}'
+			} else {
+				return x.exprs.str()
+			}
+		}
 		CTempVar {
 			return x.orig.str()
 		}