Fix Windows 64-bit build.

src/x64/assembler-x64.cc

 // Copyright 2011 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 336 matching lines @@
 Assembler::Assembler(Isolate* arg_isolate, void* buffer, int buffer_size)
     : AssemblerBase(arg_isolate),
       code_targets_(100),
       positions_recorder_(this),
       emit_debug_code_(FLAG_debug_code) {
   if (buffer == NULL) {
     // Do our own buffer management.
     if (buffer_size <= kMinimalBufferSize) {
       buffer_size = kMinimalBufferSize;
 
-      if (isolate()->assembler_spare_buffer() != NULL) {
+      if (isolate() != NULL && isolate()->assembler_spare_buffer() != NULL) {
         buffer = isolate()->assembler_spare_buffer();
         isolate()->set_assembler_spare_buffer(NULL);
       }
     }
     if (buffer == NULL) {
       buffer_ = NewArray<byte>(buffer_size);
     } else {
       buffer_ = static_cast<byte*>(buffer);
     }
     buffer_size_ = buffer_size;
@@ skipping 23 matching lines @@
   last_pc_ = NULL;
 
 #ifdef GENERATED_CODE_COVERAGE
   InitCoverageLog();
 #endif
 }
 
 
 Assembler::~Assembler() {
   if (own_buffer_) {
-    if (isolate()->assembler_spare_buffer() == NULL &&
+    if (isolate() != NULL && 
+        isolate()->assembler_spare_buffer() == NULL &&
         buffer_size_ == kMinimalBufferSize) {
       isolate()->set_assembler_spare_buffer(buffer_);
     } else {
       DeleteArray(buffer_);
     }
   }
 }
 
 
 void Assembler::GetCode(CodeDesc* desc) {
@@ skipping 102 matching lines @@
 
   // Copy the data.
   intptr_t pc_delta = desc.buffer - buffer_;
   intptr_t rc_delta = (desc.buffer + desc.buffer_size) -
       (buffer_ + buffer_size_);
   memmove(desc.buffer, buffer_, desc.instr_size);
   memmove(rc_delta + reloc_info_writer.pos(),
           reloc_info_writer.pos(), desc.reloc_size);
 
   // Switch buffers.
-  if (isolate()->assembler_spare_buffer() == NULL &&
+  if (isolate() != NULL &&
+      isolate()->assembler_spare_buffer() == NULL &&
       buffer_size_ == kMinimalBufferSize) {
     isolate()->set_assembler_spare_buffer(buffer_);
   } else {
     DeleteArray(buffer_);
   }
   buffer_ = desc.buffer;
   buffer_size_ = desc.buffer_size;
   pc_ += pc_delta;
   if (last_pc_ != NULL) {
     last_pc_ += pc_delta;
@@ skipping 2634 matching lines @@
   // specially coded on x64 means that it is a relative 32 bit address, as used
   // by branch instructions.
   return (1 << rmode_) & kApplyMask;
 }
 
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64