Adjust CV::save logic for perl522 rurban#392

This is fixing the compilation of several core tests
and introduced only one single regression which unicode sub.

SVs_PADSTALE was introduced in perl 5.8.5

lib/B/C.pm

@@ -345,6 +345,11 @@ BEGIN {
     eval q[sub SVt_PVGV() {13}];
     eval q[sub CVf_WEAKOUTSIDE() { 0x0 }]; # unused
   }
+  if ($] >=  5.008005) {
+    B->import(qw(SVs_PADSTALE)); # added with 5.8.5
+  } else {
+    eval q[sub SVs_PADSTALE() {0x0}]; # unused
+  }
   if ($] >= 5.010) {
     #require mro; # mro->import();
     # not exported:
@@ -4210,9 +4215,15 @@ sub B::CV::save {
 
   # XXX how is ANON with CONST handled? CONST uses XSUBANY [GH #246]
   if ($isconst and !is_phase_name($cvname) and
-      ( ($PERL522 and !($CvFLAGS & (CVf_ANONCONST|CVf_CONST)))
-     or (!$PERL522 and !($CvFLAGS & CVf_ANON)) )
-     ) # skip const magic blocks (Attribute::Handlers)
+    (
+      (
+        $PERL522
+        and !( $CvFLAGS & SVs_PADSTALE )
+        and !( $CvFLAGS & CVf_WEAKOUTSIDE )
+        and !( $fullname && $fullname =~ qr{^File::Glob::GLOB} and ( $CvFLAGS & (CVf_ANONCONST|CVf_CONST) )  )
+      )
+      or (!$PERL522 and !($CvFLAGS & CVf_ANON)) )
+    ) # skip const magic blocks (Attribute::Handlers)
   {
     my $stash = $gv->STASH;
     #warn sprintf("$cvstashname\::$cvname 0x%x -> XSUBANY", $CvFLAGS) if $debug{cv};