Integrate perlio:

[ 17431]
SuSE 8.0 at least needs hints to use -lgdbm for ODBM_File

[ 17432]
Core-dump prevention for
   open PIPE, "-|:stdio", "cat /etc/motd";
(root cause not yet fixed).

[ 17433]
Special case :stdio pushed method so that "-|:stdio" does
not have an uninitialized layer on top.

[ 17435]
Call $encoding->decode($sv) without a $chk argument.
This fixes modification of readonly value under use encoding().
Not a final fix as it does not warn on failed decode.

[ 17437]
perldiag patch for implied open of STDIN/STDOUT/STDERR
in wrong mode.
p4raw-link: @17437 on //depot/perlio: 2a6fd447f5201f6e744cbe03d943fde68edbbff8
p4raw-link: @17435 on //depot/perlio: f989386671918f01ee81e803b0ebff38ff623ad4
p4raw-link: @17433 on //depot/perlio: 1fd8f4ce4f455e94926dba744af1f828c467ad44
p4raw-link: @17432 on //depot/perlio: 439ba5457a8422144686c1df300aa1dde218dbfd
p4raw-link: @17431 on //depot/perlio: 526d96c3e19e37c3a741435e361e1731394e2c2d

p4raw-id: //depot/perl@17438