Update steps test to reflect deprecation of parrot_is_shared.
config::auto::pcre: 'unless' block should have been 'if'.

Clean up test files generated during configuration probe.
Avert an uninitialized value warning.

Update one copyright date.
[test] fix t/perl/Parrot_Test.t for VALGRIND

also fix Parrot::Test for valgrind with --pid--, as on darwin
coro: refactor return code. problem: wrong continuation

let Parrot_sub_continuation_rewind_environment return from_sub
for continuation.invoke.
let yield carry a 2nd state: 2 for .return
fix .return() mostly [GH# 1106]
remove unneeded empty ctx check in coroutine.invoke back from coro

changed t/pmc/coroutine.t to match the new implementation.
Fixed: 9, 13, 14, 15, 16
Remaining todo:
-  2: wrong returncc cont to label, regression (also syn_7)
- 14: wrong cont
[test] change regressing returncc label from coro to return value
trace: print Coro similar to Sub with -t1
coro: fix dead state with and without autoreset

we do not error when the coro returns from return/returncc.
we rather error when a dead coro is called, new yield state 2.