A64: Synchronize with r15545.

src/platform-macos.cc

Index: src/platform-macos.cc
diff --git a/src/platform-macos.cc b/src/platform-macos.cc
index b21166d6ce5cf643f1d73044d70f354e0cda02aa..f4d8b33817990f918c4d25eefbbcf453702f91b2 100644
--- a/src/platform-macos.cc
+++ b/src/platform-macos.cc
@@ -583,7 +583,7 @@ static void InitializeTlsBaseOffset() {
   if (kernel_version_major < 11) {
     // 8.x.x (Tiger), 9.x.x (Leopard), 10.x.x (Snow Leopard) have the
     // same offsets.
-#if defined(V8_HOST_ARCH_IA32)
+#if V8_HOST_ARCH_IA32
     kMacTlsBaseOffset = 0x48;
 #else
     kMacTlsBaseOffset = 0x60;
@@ -596,6 +596,7 @@ static void InitializeTlsBaseOffset() {
   Release_Store(&tls_base_offset_initialized, 1);
 }
 
+
 static void CheckFastTls(Thread::LocalStorageKey key) {
   void* expected = reinterpret_cast<void*>(0x1234CAFE);
   Thread::SetThreadLocal(key, expected);