Integrate perlio:

[  8281]
Tweak perlio.c so that makedef.pl-exported perlsio_binmode()
is available to be exported

[  8280]
Ilya's OS2 patch (testing for damage on Win32)

p4raw-link: @8281 on //depot/perlio: eb73becae469f5299394486e1d7e01e96646e994
p4raw-link: @8280 on //depot/perlio: 568ad336973732c4d3fa134b7dcb8e82359c1f11

p4raw-id: //depot/perl@8282