Prevent rb_define_(class|module) classes from moving

Before this commit, classes and modules would be registered with the
VM's `defined_module_hash`.  The key was the ID of the class, but that
meant that it was possible for hash collisions to occur.  The compactor
doesn't allow classes in the `defined_module_hash` to move, but if there
is a conflict, then it's possible a class would be removed from the hash
and not get pined.

This commit changes the key / value of the hash just to be the class
itself, thus preventing movement.

1 files changed, 1 insertions, 1 deletions

diff --git a/vm_core.h b/vm_core.h
index 2e8ddfe37f..2c38911d58 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -660,7 +660,7 @@ typedef struct rb_vm_struct {
     VALUE coverages;
     int coverage_mode;
 
-    VALUE defined_module_hash;
+    st_table * defined_module_hash;
 
     struct rb_objspace *objspace;