Integrate perlio:

Integrate perlio:

[ 13068]
embed.pl generated changes I forgot to include

[ 13067]
Force inclusion of both Perl_runops_* in perl itself,
so they are available for Peek.xs etc.

[ 12874]
Keep It Simple and Stupid version of readonly hash support.
- Test for SvREAONLY(hv) at a few spots in hv.c
- add the error message to perldiag.pod
- (dubious) add access::readonly() to univeral.c
- add test using above
- fixup ext/B/t/stash.t to account for access:: existing

p4raw-link: @13068 on //depot/perlio: 543c00c93a3f7ccd573dc2e23ffd06654cf38058
p4raw-link: @13067 on //depot/perlio: 60e4ec2e6ee5ed6e4095807a4e0ada718c12b221
p4raw-link: @12874 on //depot/perlio: 1b1f1335be81080356b687a63b64fde210a3b697

p4raw-id: //depot/perl@13069