win32 io: fix open append
win32 io: fix open append

t/pmc/io.t test 10 failed on win32 because PIO_F_APPEND was never checked.

tkob/parrot,parrot/parrot,tkob/parrot,parrot/parrot,FROGGS/parrot,tkob/parrot,tkob/parrot,youprofit/parrot,FROGGS/parrot,parrot/parrot,tkob/parrot,FROGGS/parrot,tkob/parrot,FROGGS/parrot,youprofit/parrot,FROGGS/parrot,tkob/parrot,youprofit/parrot,FROGGS/parrot,parrot/parrot,youprofit/parrot,youprofit/parrot,youprofit/parrot,youprofit/parrot,parrot/parrot,FROGGS/parrot,FROGGS/parrot,tkob/parrot,youprofit/parrot