[Patch, libstdc++] Add specific error message into exceptions

[Jonathan Wakely]

On 28/08/15 20:44 -0700, Tim Shen wrote:
>On Fri, Aug 28, 2015 at 11:23 AM, Tim Shen <timshen@google.com> wrote:
>> So is it good to have an owned raw pointer stored in runtime_error,
>> pointing to a heap allocated char chunk, which will be deallocated in
>> regex_error's dtor?
>
>I just put a string member into regex_error, completely ignoring the
>storage in std::runtime_error.

That's still an ABI change, so not OK.