[Patch, regex, libstdc++/69794] Unify special character parsing

[Jonathan Wakely]

On 13/02/16 11:13 -0800, Tim Shen wrote:
>I did it wrong in r227289 - I ignored the "\n" special case in grep.
>Turns out using code to handle special cases is error prone, so I
>turned to use data (_M_grep_spec_char and _M_egrep_spec_char).

Those new members change the size of the type, so are an ABI change.

Couldn't they be static members?