remove most uses of Isolate::Current in arch specific files

src/arm/assembler-arm.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 306 matching lines @@
   // Patch the code at the current address with a call to the target.
   UNIMPLEMENTED();
 }
 
 
 // -----------------------------------------------------------------------------
 // Implementation of Operand and MemOperand
 // See assembler-arm-inl.h for inlined constructors
 
 Operand::Operand(Handle<Object> handle) {
-#ifdef DEBUG
-  Isolate* isolate = Isolate::Current();
-#endif
   AllowDeferredHandleDereference using_raw_address;
   rm_ = no_reg;
   // Verify all Objects referred by code are NOT in new space.
   Object* obj = *handle;
-  ASSERT(!isolate->heap()->InNewSpace(obj));
   if (obj->IsHeapObject()) {
+    ASSERT(!HeapObject::cast(obj)->GetHeap()->InNewSpace(obj));
     imm32_ = reinterpret_cast<intptr_t>(handle.location());
     rmode_ = RelocInfo::EMBEDDED_OBJECT;
   } else {
     // no relocation needed
     imm32_ = reinterpret_cast<intptr_t>(obj);
     rmode_ = RelocInfo::NONE32;
   }
 }
 
 
@@ skipping 3008 matching lines @@
 
   // Since a constant pool was just emitted, move the check offset forward by
   // the standard interval.
   next_buffer_check_ = pc_offset() + kCheckPoolInterval;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM