[vm] Fix some TSAN failures. Migrate remaining uses of AtomicOperations to std::atomic.

Change-Id: I195232311a146248c601ef84640758db59083d12
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121200
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>

Author: rmacnak-google

runtime/platform/atomic.h

@@ -63,67 +63,6 @@ class RelaxedAtomic {
   std::atomic<T> value_;
 };
 
-class AtomicOperations : public AllStatic {
- public:
-  // Atomically fetch the value at p and increment the value at p.
-  // Returns the original value at p.
-  static uintptr_t FetchAndIncrement(uintptr_t* p);
-  static intptr_t FetchAndIncrement(intptr_t* p);
-
-  // Atomically increment the value at p by 'value'.
-  static void IncrementBy(intptr_t* p, intptr_t value);
-  static void IncrementInt64By(int64_t* p, int64_t value);
-
-  // Atomically fetch the value at p and decrement the value at p.
-  // Returns the original value at p.
-  static uintptr_t FetchAndDecrement(uintptr_t* p);
-  static intptr_t FetchAndDecrement(intptr_t* p);
-
-  // Atomically decrement the value at p by 'value'.
-  static void DecrementBy(intptr_t* p, intptr_t value);
-
-  // Atomically compare *ptr to old_value, and if equal, store new_value.
-  // Returns the original value at ptr.
-  static uword CompareAndSwapWord(uword* ptr, uword old_value, uword new_value);
-  static uint32_t CompareAndSwapUint32(uint32_t* ptr,
-                                       uint32_t old_value,
-                                       uint32_t new_value);
-
-  // Performs a load of a word from 'ptr', but without any guarantees about
-  // memory order (i.e., no load barriers/fences).
-  template <typename T>
-  static T LoadRelaxed(T* ptr) {
-    return *static_cast<volatile T*>(ptr);
-  }
-
-  template <typename T>
-  static T LoadAcquire(T* ptr);
-
-  template <typename T>
-  static void StoreRelease(T* ptr, T value);
-
-  template <typename T>
-  static T* CompareAndSwapPointer(T** slot, T* old_value, T* new_value) {
-    return reinterpret_cast<T*>(AtomicOperations::CompareAndSwapWord(
-        reinterpret_cast<uword*>(slot), reinterpret_cast<uword>(old_value),
-        reinterpret_cast<uword>(new_value)));
-  }
-};
-
 }  // namespace dart
 
-#if defined(HOST_OS_ANDROID)
-#include "platform/atomic_android.h"
-#elif defined(HOST_OS_FUCHSIA)
-#include "platform/atomic_fuchsia.h"
-#elif defined(HOST_OS_LINUX)
-#include "platform/atomic_linux.h"
-#elif defined(HOST_OS_MACOS)
-#include "platform/atomic_macos.h"
-#elif defined(HOST_OS_WINDOWS)
-#include "platform/atomic_win.h"
-#else
-#error Unknown target os.
-#endif
-
 #endif  // RUNTIME_PLATFORM_ATOMIC_H_