Some BIOSes incorrectly use standard memory resource ranges to list
the memory ranges that they decode for downstream devices rather than
creating ResourceProducer range resource entries.  The result is that
we allocate the full range to the PCI root bridge device causing
allocations in child devices to all fail.

As a workaround, ignore any standard memory resources on a PCI root
bridge device.  It is normal for a PCI root bridge to allocate an I/O
resource for the I/O ports used for PCI config access, but I have not
seen any PCI root bridges that legitimately allocate a memory resource.

Reviewed by:	jkim
MFC after:	1 week
Adjust r239672 from rrs and r258821 from eadler.

By definition, the very first FIN is not a duplicate. Process it normally
and don't feed it to congestion control as though it were a dupe.  Don't
prevent CC from seeing later dupe acks while in a half close state.