A new patch for libstdc++

[Joe Buck]

> It turned out the OUTOFRANGE bug is triggered by a typo. But you
> still cannot throw out_of_range in string. Here is a new patch.

I still haven't seen any test case that backs up this assertion.
Yes, recursion may result (the constructor that is throwing will
call the identical constructor), but as best I can tell, the second
call can never throw, therefore there is no problem.  If you believe
otherwise, please post a case that causes an infinite recursion.