Create shim targets for most commonly used TSL headers in preparation for updating users

PiperOrigin-RevId: 707667247

Author: ddunl

tsl/platform/BUILD

@@ -1,4 +1,4 @@
-/* Copyright 2015 The TensorFlow Authors. All Rights Reserved.
+/* Copyright 2024 The TensorFlow Authors. All Rights Reserved.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -12,54 +12,10 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 ==============================================================================*/
+
 #ifndef TENSORFLOW_TSL_PLATFORM_ENV_TIME_H_
 #define TENSORFLOW_TSL_PLATFORM_ENV_TIME_H_
 
-#include <stdint.h>
-
-#include "tsl/platform/types.h"
-
-namespace tsl {
-
-/// \brief An interface used by the tsl implementation to
-/// access timer related operations.
-class EnvTime {
- public:
-  static constexpr uint64 kMicrosToPicos = 1000ULL * 1000ULL;
-  static constexpr uint64 kMicrosToNanos = 1000ULL;
-  static constexpr uint64 kMillisToMicros = 1000ULL;
-  static constexpr uint64 kMillisToNanos = 1000ULL * 1000ULL;
-  static constexpr uint64 kNanosToPicos = 1000ULL;
-  static constexpr uint64 kSecondsToMillis = 1000ULL;
-  static constexpr uint64 kSecondsToMicros = 1000ULL * 1000ULL;
-  static constexpr uint64 kSecondsToNanos = 1000ULL * 1000ULL * 1000ULL;
-
-  EnvTime() = default;
-  virtual ~EnvTime() = default;
-
-  /// \brief Returns the number of nano-seconds since the Unix epoch.
-  static uint64 NowNanos();
-
-  /// \brief Returns the number of micro-seconds since the Unix epoch.
-  static uint64 NowMicros() { return NowNanos() / kMicrosToNanos; }
-
-  /// \brief Returns the number of seconds since the Unix epoch.
-  static uint64 NowSeconds() { return NowNanos() / kSecondsToNanos; }
-
-  /// \brief A version of NowNanos() that may be overridden by a subclass.
-  virtual uint64 GetOverridableNowNanos() const { return NowNanos(); }
-
-  /// \brief A version of NowMicros() that may be overridden by a subclass.
-  virtual uint64 GetOverridableNowMicros() const {
-    return GetOverridableNowNanos() / kMicrosToNanos;
-  }
-
-  /// \brief A version of NowSeconds() that may be overridden by a subclass.
-  virtual uint64 GetOverridableNowSeconds() const {
-    return GetOverridableNowNanos() / kSecondsToNanos;
-  }
-};
-
-}  // namespace tsl
+#include "xla/tsl/platform/env_time.h"
 
 #endif  // TENSORFLOW_TSL_PLATFORM_ENV_TIME_H_