Old version of PDB files can have a stream #4 which is not an IPI stream
Available documentation isn't 100% clear about when IPI has been
introduced.
So decide that IPI is present when header of stream looks like a type
stream header.
Signed-off-by: Eric Pouech <eric.pouech@gmail.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>