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, 2 insertions, 2 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_lightcache.c b/source/blender/draw/engines/eevee/eevee_lightcache.c
index 275e185a0e4..05aea652591 100644
--- a/source/blender/draw/engines/eevee/eevee_lightcache.c
+++ b/source/blender/draw/engines/eevee/eevee_lightcache.c
@@ -138,7 +138,7 @@ typedef struct EEVEE_LightBake {
   float vis_res;
   /** Result of previous light bounce. */
   GPUTexture *grid_prev;
-  /** Pointer to the id.data of the probe object. */
+  /** Pointer to the owner_id of the probe object. */
   LightProbe **grid_prb;
 
   /* Reflection probe */
@@ -148,7 +148,7 @@ typedef struct EEVEE_LightBake {
   int ref_cube_res;
   /** Index of the current cube. */
   int cube_offset;
-  /** Pointer to the id.data of the probe object. */
+  /** Pointer to the owner_id of the probe object. */
   LightProbe **cube_prb;
 
   /* Dummy Textures */