Correct err msg when calling stub w/no autoload fb

If an AUTOLOAD subroutine loads a sub by assigning to the glob, there
may be code elsewhere that has a reference to a stub, that is now
assigned over.  To cope with this situation, calls to undefined sub-
routines will fall back to whatever sub is in the subroutine’s owner
typeglob.  This has been the case since Perl 5.000.

But the error message that occurs if the typeglob happens to have no
sub in it is wrong:

$ perl -e '
   my $foosub = \&foo;
   undef *foo;
   &$foosub;
  '
Not a CODE reference at -e line 4.

as opposed to this:

$ perl -e '
   my $foosub = \&foo;
   &$foosub;
  '
Undefined subroutine &main::foo called at -e line 3.

They should both produce the same error message, because $foosub is a
code reference, albeit without a body.

1 files changed, 1 insertions, 0 deletions

diff --git a/MANIFEST b/MANIFEST
index 7a5d0c072c..1396660928 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -5034,6 +5034,7 @@ t/lib/compmod.pl		Helper for 1_compile.t
 t/lib/croak/mg			Test croak calls from mg.c
 t/lib/croak/op			Test croak calls from op.c
 t/lib/croak/pp_ctl		Test croak calls from pp_ctl.c
+t/lib/croak/pp_hot		Test croak calls from pp_hot.c
 t/lib/croak.t			Test calls to Perl_croak() in the C source.
 t/lib/croak/toke		Test croak calls from toke.c
 t/lib/cygwin.t			Builtin cygwin function tests