Keep MRO caches around during hv_clear

This allows it to delete PL_isarev entries.

mro_isa_changed_in only deletes items mentioned in HvMROMETA(hv)->isa,
so it must be present.

1 files changed, 5 insertions, 1 deletions

diff --git a/t/mro/isarev.t b/t/mro/isarev.t
index 3c3692e5ad..3bd543d33e 100644
--- a/t/mro/isarev.t
+++ b/t/mro/isarev.t
@@ -10,7 +10,7 @@ BEGIN {
 
 use strict;
 use warnings;
-plan(tests => 23);
+plan(tests => 24);
 
 use mro;
 
@@ -141,3 +141,7 @@ i buki => qw [], "undeffing a package glob deletes isarev entries";
 *bar:: = *baz::;
 i phoo => qw [],
  'clobbering a class w/multiple layers of subclasses updates its parent';
+
+@Thrat::ISA = 'Smin';
+%Thrat:: = ();
+i Smin => qw [], '%Package:: list assignment';