Integrate perlio:
Nicholas Clark [Mon, 12 Feb 2001 16:43:51 +0000 (16:43 +0000)]
[  8830]
Apply the spirit of patch from Nicholas Clark:
Subject: [PATCH] Re: extensions that provide layers
Message-Id: <20010212164350.Q3652@plum.flirble.org>

p4raw-link: @8830 on //depot/perlio: 64977eb6138422a1560c20575c46ef223d980150

p4raw-id: //depot/perl@8832


Trivial merge