[PATCH][libstdc++-v3 parallel mode] Patch for PR 39546

[Paolo Carlini]

Johannes Singler wrote:
> Better now?
>   
Yes, not perfect, however ;) Please add a

   bool test __attribute__((unused)) = true;

variable at the beginning of test01; add a space after the open brace of
VERIFY( and before the closed one; move the comment about the PR before
test01, instead of before main; Ok with those changes.

Thanks!
Paolo.