Revert "Strengthen weak refs when sorting in-place"

This reverts commit f6107ca.

See RT #132142.

For now, re-introduce the bug that fails to convert weak refs to strong
refs when sorting in place.

This is commit 2 of 2.

Author: iabyn

pp_sort.c

@@ -1094,9 +1094,6 @@ PP(pp_sort)
                     base[i] = newSVsv(sv);
                 else
                     SvREFCNT_inc_simple_void_NN(sv);
-
-                if (SvWEAKREF(sv))
-                    sv_rvunweaken(sv);
             }
             av_clear(av);
             if (max > 0) {

t/op/sort.t

@@ -7,7 +7,7 @@ BEGIN {
     set_up_inc('../lib');
 }
 use warnings;
-plan(tests => 200);
+plan(tests => 199);
 
 # these shouldn't hang
 {
@@ -492,18 +492,7 @@ cmp_ok($x,'eq','123',q(optimized-away comparison block doesn't take any other ar
     @a = sort { $a <=> $b } @a;
     $$r = "z";
     is ("@a", "3 4 5", "RT #128340");
-}
 
-# in-place sorting of weak references
-SKIP: {
-    skip_if_miniperl("no dynamic loading on miniperl, no extension Scalar::Util", 1);
-    require Scalar::Util;
-    my @a = map { \(my $dummy = $_) } qw(c a d b);
-    my $r = $a[1];
-    Scalar::Util::weaken($a[1]);
-    @a = sort { $$a cmp $$b } @a;
-    undef $r;
-    ok defined $a[0] && ${$a[0]} eq 'a', "in-place sort strengthens weak references";
 }
 
 # Test optimisations of reversed sorts. As we now guarantee stability by