[PATCH] c++, libstdc++, v2: Implement C++26 P3074R7, P3726R0 and CWG3189 - trivial unions [PR119059]

[Marek Polacek]

On Wed, May 20, 2026 at 05:40:39PM +0200, Jakub Jelinek wrote:
>  bool
> -reduced_constant_expression_p (tree t, tree sz /* = NULL_TREE */)
> +reduced_constant_expression_p (tree t, tree sz /* = NULL_TREE */,
> +			       bool union_elemental_subobject /* = false */)

Please document the new parm.

> @@ -7817,7 +7882,7 @@ static tree
>  cxx_eval_store_expression (const constexpr_ctx *ctx, tree t,
>  			   value_cat lval,
>  			   bool *non_constant_p, bool *overflow_p,
> -			   tree *jump_target)
> +			   tree *jump_target, bool start_lifetime/*=false*/)

Here too.

Marek