C: fix %dumped_package, add walk_syms debugging

%dumped_package was not added in walksymtable, as the prefix always ended in "::"
C: tune %dumped_package

still the same core regressions, much less testfast failures
set dumped_package in savecv, and in "force saving of XSLoader"

skip force warnings when Carp is not dumped (not included).

remaining regressions:
t/issue24.t     (dbm)
  Failed tests:  2-3
t/cc.t          (-fstash)
  Failed test:  46

core: (mostly static warn overwrites)
t/C-COMPILED/CORE--mro--next_edgecases.t               (Wstat: 768 Tests: 23 Failed: 3)
  Failed tests:  17-18, 22
  Non-zero exit status: 3 message for your changes. Lines starting
t/C-COMPILED/CORE--mro--isarev==SIG-0.t                (Wstat: 0 Tests: 23 Failed: 0)
  TODO passed:   7
t/C-COMPILED/CORE--op--closure.t                       (Wstat: 1024 Tests: 23 Failed: 4)
  Failed tests:  10-11, 20-21h your local commits)
  Non-zero exit status: 4
t/C-COMPILED/CORE--op--dbm.t                           (Wstat: 1024 Tests: 23 Failed: 4)
  Failed tests:  10-11, 20-21
  Non-zero exit status: 4
t/C-COMPILED/CORE--op--inccode.t                       (Wstat: 768 Tests: 23 Failed: 3)
  Failed tests:  17-18, 22
  Non-zero exit status: 3
t/C-COMPILED/CORE--op--length.t                        (Wstat: 768 Tests: 23 Failed: 3)
  Failed tests:  17-18, 22
  Non-zero exit status: 3
t/C-COMPILED/CORE--op--sigdispatch.t                   (Wstat: 768 Tests: 23 Failed: 3)
  Failed tests:  17-18, 22
  Non-zero exit status: 3
t/C-COMPILED/CORE--op--undef.t                         (Wstat: 768 Tests: 23 Failed: 3)
  Failed tests:  17-18, 22
  Non-zero exit status: 3
t/C-COMPILED/CORE--re--charset.t                       (Wstat: 768 Tests: 23 Failed: 3)
  Failed tests:  17-18, 22
  Non-zero exit status: 3
t/C-COMPILED/CORE--re--pat_advanced==SIG-330.t         (Wstat: 0 Tests: 23 Failed: 0)
  TODO passed:   17
t/C-COMPILED/CORE--re--substr.t                        (Wstat: 768 Tests: 23 Failed: 3)
  Failed tests:  17-18, 22
  Non-zero exit status: 3