[perl #107636] Make Carp::longmess work inside die override

When PL_last_in_gv (and hence $.) is set, Carp::longmess uses
eval { die } to find out what handle and line number perl will append
to the error message.

It was not qualifying the die with CORE::, so a CORE::GLOBAL::die
override that itself calls Carp::longmess would result in infinite
recursion if that override were installed before Carp loaded.

This broke Class::Scaffold’s tests, which began to hang.

dist/Carp/lib/Carp.pm

@@ -291,7 +291,7 @@ sub ret_backtrace {
         local $@ = '';
         local $SIG{__DIE__};
         eval {
-            die;
+            CORE::die;
         };
         if($@ =~ /^Died at .*(, <.*?> line \d+).$/ ) {
             $mess .= $1;

dist/Carp/t/Carp.t

@@ -3,7 +3,7 @@ no warnings "once";
 use Config;
 
 use IPC::Open3 1.0103 qw(open3);
-use Test::More tests => 59;
+use Test::More tests => 60;
 
 sub runperl {
     my(%args) = @_;
@@ -430,6 +430,20 @@ $@ =~ s/\n.*//; # just check first line
 is $@, "heek at ".__FILE__." line ".(__LINE__-2).", <DATA> line 2.\n",
     'last handle line num is mentioned';
 
+like(
+  runperl(
+    prog => q<
+      open FH, q-Makefile.PL-;
+      <FH>;  # set PL_last_in_gv
+      BEGIN { *CORE::GLOBAL::die = sub { die Carp::longmess(@_) } };
+      use Carp;
+      die fumpts;
+    >,
+  ),
+  qr 'fumpts',
+  'Carp::longmess works inside CORE::GLOBAL::die',
+);
+
 
 # New tests go here