ClangFormat: apply to source, most of intern

Apply clang format as proposed in T53211.

For details on usage and instructions for migrating branches
without conflicts, see:

https://wiki.blender.org/wiki/Tools/ClangFormat

source/blender/python/gpu/gpu_py_batch.h

@@ -27,15 +27,15 @@
 
 extern PyTypeObject BPyGPUBatch_Type;
 
-#define BPyGPUBatch_Check(v)          (Py_TYPE(v) == &BPyGPUBatch_Type)
+#define BPyGPUBatch_Check(v) (Py_TYPE(v) == &BPyGPUBatch_Type)
 
 typedef struct BPyGPUBatch {
-	PyObject_VAR_HEAD
-	/* The batch is owned, we may support thin wrapped batches later. */
-	struct GPUBatch *batch;
+  PyObject_VAR_HEAD
+      /* The batch is owned, we may support thin wrapped batches later. */
+      struct GPUBatch *batch;
 #ifdef USE_GPU_PY_REFERENCES
-	/* Just to keep a user to prevent freeing buf's we're using */
-	PyObject *references;
+  /* Just to keep a user to prevent freeing buf's we're using */
+  PyObject *references;
 #endif
 } BPyGPUBatch;