[Patch] Improve the old fix for 11095

[Benjamin Kosnik]

>Benjamin, I'm not sure to understand what you mean... To my best knowledge,
>memory allocated with __builtin_alloca, or plain 'alloca' for that matter,
>is freed at the end of the /function/ not at the end of the block! The glibc
>info pages are very clear about that!

Ouch! You and Jason are correct, sorry for my temporary confusion.

>And, anyway, memory allocated with __builtin_alloca is already used outside
>the nearest enclosing scope in /many/ places in locale_facets.tcc.

..yes. I don't know what I was thinking.

best,
benjamin