[patch] Make std::tr1::shared_ptr thread-safe.

[Paolo Carlini]

Jonathan Wakely wrote:

>It was that (very useful) document that gave me the idea of using
>dg-excess-errors :-)   I was going by the bit that said:
>
>    Moreover, this command can be useful to take care of all the
>    additional information notes that the compiler emits to help the
>    user fixing the problem: since they all look like: foo.c:26: note:
>    blah , it is sufficient to use { dg-excess-errors "note" } to match
>    all of them.
>
>Since in those tests the real error has been caught on the line that
>won't compile, the other errors are just the "candidates are" notes that
>are printed. We're not matching anything very specific in those notes,
>so (I thought) we don't care e.g. what other constructors there are as
>long as we can't construct from an auto_ptr rvalue.
>  
>
Ah, I didn't know that, additionall to those directives we also have a
plain
dg-error at the line of the actual error. In that case, you are right,
this is a
good use for dg-excess-errors, please don't change that part of the patch!

Thanks,
Paolo.