msvcirt/tests: Add initial tests for streambuf

[Piotr Caban]

On 06/02/15 12:47, Iván Matellanes wrote:
> +todo_wine{
> +    /* constructors */
> +    call_func1(p_streambuf_ctor, &sb);
You'll need to add streambuf_ctor stub in wine before you can test it. 
Currently the tests will fail with exception. Please also set &sb memory 
to something so you can detect uninitialized values.

Please also call streambuf_dtor.

Cheers,
Piotr