RNA: Cleanup PointerRNA struct

The old layout of `PointerRNA` was confusing for historic reasons:
```
typedef struct PointerRNA {
  struct {
    void *data;
  } id;

  struct StructRNA *type;
  void *data;
} PointerRNA;
```

This patch updates it to:
```
typedef struct PointerRNA {
  struct ID *owner_id;
  struct StructRNA *type;
  void *data;
} PointerRNA;
```

Throughout the code base `id.data` was replaced with `owner_id`.
Furthermore, many explicit pointer type casts were added which
were implicit before. Some type casts to `ID *` were removed.

Reviewers: brecht, campbellbarton

Differential Revision: https://developer.blender.org/D5558

1 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/editors/interface/interface_eyedropper_driver.c b/source/blender/editors/interface/interface_eyedropper_driver.c
index c1aee190cd3..e6fc52bc3bc 100644
--- a/source/blender/editors/interface/interface_eyedropper_driver.c
+++ b/source/blender/editors/interface/interface_eyedropper_driver.c
@@ -116,10 +116,10 @@ static void driverdropper_sample(bContext *C, wmOperator *op, const wmEvent *eve
     /* Now create driver(s) */
     if (target_path && dst_path) {
       int success = ANIM_add_driver_with_target(op->reports,
-                                                ddr->ptr.id.data,
+                                                ddr->ptr.owner_id,
                                                 dst_path,
                                                 ddr->index,
-                                                target_ptr->id.data,
+                                                target_ptr->owner_id,
                                                 target_path,
                                                 target_index,
                                                 flag,
@@ -130,7 +130,7 @@ static void driverdropper_sample(bContext *C, wmOperator *op, const wmEvent *eve
         /* send updates */
         UI_context_update_anim_flag(C);
         DEG_relations_tag_update(CTX_data_main(C));
-        DEG_id_tag_update(ddr->ptr.id.data, ID_RECALC_TRANSFORM | ID_RECALC_GEOMETRY);
+        DEG_id_tag_update(ddr->ptr.owner_id, ID_RECALC_TRANSFORM | ID_RECALC_GEOMETRY);
         WM_event_add_notifier(C, NC_ANIMATION | ND_FCURVES_ORDER, NULL);  // XXX
       }
     }