Integrate perlio:

[  9300]
Don't include $@ in not ok message.

[  9298]
Give a meaning to '&' in n-arg open case:
open($fh,"<&",$scalar);
$scalar can be:
- an integer which does "fdopen"
open($fh,"<&",2); # like open($fh,"<&2")
- something that will yield a file handle via sv_2io()
useful for dup'ing anonymous handles.
e.g.:
open(my $fh,"<&",\*STDIN);
open(my $dup,"<&",$fh);

[  9297]
Implement open($fh,"-|",prog,args...) for HAS_FORK cases.

[  9296]
Re-instate warnings for 'eof STDOUT' etc. by marking STD* as appropriate IoTYPE.

[  9295]
If stdin, stdout or stderr get opened in unexpected read/write state
then warn at time of open not at time of use.

[  9294]
Die on n-arg open(...,"",xxx,yyy,...)
- redirect pipe cases to PerlProc_popen_list() (which just croaks for now)
- die on read/write cases so we can decide what it means later.

[  9293]
perlio tweaks (reported by Nicholas Clark)
Line buffer ttys, PerlIOBuf_tell() on unseekable off-by one,
error check in Pendinf_read().

p4raw-link: @9300 on //depot/perlio: 4fbc943a81ac8168e4ba63497561c515427127d8
p4raw-link: @9298 on //depot/perlio: e620cd7232b242c1500abd8a6a5b86efdf1c5c2b
p4raw-link: @9297 on //depot/perlio: 1f852d0d1f9745d51afb4cb836d527bbbac0c64e
p4raw-link: @9296 on //depot/perlio: a04651f440b69a3f6af9f5fcf427068253775945
p4raw-link: @9295 on //depot/perlio: a00b5bd33cb12556305f4526d4870e67e2ca9517
p4raw-link: @9294 on //depot/perlio: 4a7d1889681c73a99b9a39d8a3d3760367674002
p4raw-link: @9293 on //depot/perlio: 1f47406448f2d51ae8241e146df3675f96b72815

p4raw-id: //depot/perl@9301