Integrate perlio:

[  8049]
UTF8 output prework.
- Store $\ and $, as SVs so they can have SvUTF8 flag
- use do_print() rather than raw PerlIO_write() to print them.

p4raw-link: @8049 on //depot/perlio: 7889fe52c8bdedf274e4826ad460ef6c3606ca6a

p4raw-id: //depot/perl@8051

diff --cc perl.c
Simple merge