Clean up the usage of V8_TARGET_ARCH_${arch} and V8_HOST_ARCH_${arch}

src/atomicops.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 136 matching lines @@
 Atomic64 Acquire_Load(volatile const Atomic64* ptr);
 Atomic64 Release_Load(volatile const Atomic64* ptr);
 #endif  // V8_HOST_ARCH_64_BIT
 
 } }  // namespace v8::internal
 
 // Include our platform specific implementation.
 #if defined(THREAD_SANITIZER)
 #include "atomicops_internals_tsan.h"
 #elif defined(_MSC_VER) && \
-  (defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_X64))
+  (V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64)
 #include "atomicops_internals_x86_msvc.h"
 #elif defined(__APPLE__) && \
-  (defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_X64))
+  (V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64)
 #include "atomicops_internals_x86_macosx.h"
 #elif defined(__GNUC__) && \
-  (defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_X64))
+  (V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64)
 #include "atomicops_internals_x86_gcc.h"
-#elif defined(__GNUC__) && defined(V8_HOST_ARCH_ARM)
+#elif defined(__GNUC__) && V8_HOST_ARCH_ARM
 #include "atomicops_internals_arm_gcc.h"
-#elif defined(__GNUC__) && defined(V8_HOST_ARCH_MIPS)
+#elif defined(__GNUC__) && V8_HOST_ARCH_MIPS
 #include "atomicops_internals_mips_gcc.h"
 #else
 #error "Atomic operations are not supported on your platform"
 #endif
 
 #endif  // V8_ATOMICOPS_H_