Cleanup: Cycles: Remove unneeded oneAPI double emulation for NanoVDB

Pull Request: https://projects.blender.org/blender/blender/pulls/132361

intern/cycles/kernel/device/oneapi/context_begin.h

@@ -2,41 +2,7 @@
  *
  * SPDX-License-Identifier: Apache-2.0 */
 
-#ifdef WITH_NANOVDB
-/* Data type to replace `double` used in the NanoVDB headers. Cycles don't need doubles, and is
- * safer and more portable to never use double datatype on GPU.
- * Use a special structure, so that the following is true:
- * - No unnoticed implicit cast or mathematical operations used on scalar 64bit type
- *   (which rules out trick like using `uint64_t` as a drop-in replacement for double).
- * - Padding rules are matching exactly `double`
- *   (which rules out array of `uint8_t`). */
-struct ccl_vdb_double_t {
-  union ccl_vdb_helper_t {
-    double d;
-    uint64_t i;
-  };
-
-  uint64_t i;
-  ccl_vdb_double_t(double value)
-  {
-    ccl_vdb_helper_t helper;
-    helper.d = value;
-    i = helper.i;
-  }
-  /* We intentionally allow conversion to float in order to workaround compilation errors
-   * for defined math functions that take doubles. */
-  operator float() const
-  {
-    ccl_vdb_helper_t helper;
-    helper.i = i;
-    return (float)helper.d;
-  }
-};
-
-#  define double ccl_vdb_double_t
-#  include "kernel/util/nanovdb.h"
-#  undef double
-#endif
+#include "kernel/util/nanovdb.h"
 
 /* clang-format off */
 struct ONEAPIKernelContext : public KernelGlobalsGPU {