Fix T54098: Crash existing /w dyntopo sculpt

Optionally don't remap indices for objects.

Checking all objects parent's would reference a freed pointer
while freeing all objects.

In the case of dynamic topology there is no use in keeping track
of hook/vertex-parent indices.

Also disable this when creating meshes for undo storage
since adding an undo step shouldn't be modifying other objects.

source/blender/python/bmesh/bmesh_py_types.c

@@ -904,7 +904,11 @@ static PyObject *bpy_bmesh_to_mesh(BPy_BMesh *self, PyObject *args)
 	/* python won't ensure matching uv/mtex */
 	BM_mesh_cd_validate(bm);
 
-	BM_mesh_bm_to_me(bm, me, (&(struct BMeshToMeshParams){0}));
+	BM_mesh_bm_to_me(
+	        bm, me,
+	        (&(struct BMeshToMeshParams){
+	            .calc_object_remap = true,
+	        }));
 
 	/* we could have the user do this but if they forget blender can easy crash
 	 * since the references arrays for the objects derived meshes are now invalid */