builtin: fix int.str_l() integer overflow (#25458)

Author: kbkpbot

vlib/builtin/int.v

@@ -74,6 +74,17 @@ fn (nn int) str_l(max int) string {
 			return '0'
 		}
 
+		// overflow protect
+		$if new_int ? && x64 {
+			if n == min_i64 {
+				return '-9223372036854775808'
+			}
+		} $else {
+			if n == min_i32 {
+				return '-2147483648'
+			}
+		}
+
 		mut is_neg := false
 		if n < 0 {
 			n = -n