C: special-case Coro jit

need to force reloading Coro::State::_jit, so that Coro::State::_jit
gets a proper ROOT assigned and the CV saved as such.
WIP In the boot_Coro__State step we now fall into READONLY no_modify croaks.
t/issue293.t: added
C: unREADONLY before booting Coro::State (special-case Coro)
t/issue293: unTODO passing test. only one test so far
Changes: Coro fixes (#293)

reload Coro jit and SvREADONLY_off some of its XS symbols
CORE/re tests: wontfix #328, #329 re-eval with lexicals/globals

re-eval accessing globals with shadowed lexicals (same name) are not supported
and lexicals are also instable upstyream, using a broken Perl_sv_compile_2op_is_broken()
at regcomp.c:6819 compiler function.

TODO the other failing re CORE tests.
One new regression: re--reg_namedcapture==SIG-344.t
Makefile.PL: add testcore-log
t/CORE reg_namedcapture.t works fine non-DEBUGGING
log: use non-debugging 5.8.5 for the module test
t/CORE/mro/isarev.t: mark random SEGV in the test source

caused by gp_free of a static FILE_HEK in glob_assign_glob #282
C 1.46_05: add HINT_RE_EVAL for re-eval groups

we need to set the hints, because we pregcomp now at run-time, not compile-time
fixes one of the re-eval tests #135, but not the lexical/global wontfix errors with
sv_compile_2op_is_broken()
We declare unimported constants just for the parser as 0x0
t/testc.sh 135 testcase: Eval-group not allowed at runtime
C: fix READONLY magic hashes >5.20 #273

need to call SvREADONLY_on after sv_magic, otherwise we get
a Perl_croak_no_modify().
This scenario only appears since 5.20 with H magic.
MANIFEST: reorder 2 lines for t/manifest.t
C: whitespace only
Changes: add latest changelog lines
C: Fixup READONLY magic hashes for <5.14 #273

<5.14 c magic was missing causing test #16 to fail.
%main:: 'c' magic for tie:
  hv0 = gv_stashpvn("main", 4, 0);/* get main:: stash */
  /* AMT overload table for the stash hv0 is generated dynamically */
  SvSTASH_set((HV*)&sv_list[2], (HV*)hv0);
  SvREFCNT((SV*)hv0) += 1;
  ++PL_sv_objcount;
t/issue251.t: add the 2 baffling #290 testcases

defined creates a CV as side-effect, exists not
testcases and workarounds for subname static "pkg::name" #345