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

src/heap.cc

 // Copyright 2012 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 48 matching lines @@
 #endif
 
 namespace v8 {
 namespace internal {
 
 
 Heap::Heap()
     : isolate_(NULL),
 // semispace_size_ should be a power of 2 and old_generation_size_ should be
 // a multiple of Page::kPageSize.
-#if defined(V8_TARGET_ARCH_X64)
+#if V8_TARGET_ARCH_X64
 #define LUMP_OF_MEMORY (2 * MB)
       code_range_size_(512*MB),
 #else
 #define LUMP_OF_MEMORY MB
       code_range_size_(0),
 #endif
 #if defined(ANDROID)
       reserved_semispace_size_(4 * Max(LUMP_OF_MEMORY, Page::kPageSize)),
       max_semispace_size_(4 * Max(LUMP_OF_MEMORY, Page::kPageSize)),
       initial_semispace_size_(Page::kPageSize),
@@ skipping 8035 matching lines @@
   if (FLAG_parallel_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal