Refactor MemoryAllocator to allow big normal pages

src/ia32/codegen-ia32.cc

 // 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 10231 matching lines @@
     __ pop(edi);
     __ ret(0);
   }
 
   CodeDesc desc;
   masm.GetCode(&desc);
   ASSERT(desc.reloc_size == 0);
 
   // Copy the generated code into an executable chunk and return a pointer
   // to the first instruction in it as a C++ function pointer.
-  LargeObjectChunk* chunk = LargeObjectChunk::New(desc.instr_size, EXECUTABLE);
-  if (chunk == NULL) return &MemCopyWrapper;
-  memcpy(chunk->GetStartAddress(), desc.buffer, desc.instr_size);
-  CPU::FlushICache(chunk->GetStartAddress(), desc.instr_size);
-  return FUNCTION_CAST<MemCopyFunction>(chunk->GetStartAddress());
+  size_t size = RoundUp(desc.instr_size, OS::AllocateAlignment());
+  void* base = VirtualMemory::ReserveRegion(size);
+  if (base == NULL || !VirtualMemory::CommitRegion(base, size, true)) {
+    return &MemCopyWrapper;
+  }
+  memcpy(base, desc.buffer, desc.instr_size);
+  CPU::FlushICache(base, desc.instr_size);
+  return FUNCTION_CAST<MemCopyFunction>(reinterpret_cast<Address>(base));
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32