Make subtype test cache stub shared between isolates.

runtime/vm/assembler_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // NOLINT
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 1949 matching lines @@
   ASSERT(RawObject::kClassIdTagPos == 16);
   ASSERT(RawObject::kClassIdTagSize == 16);
   const intptr_t class_id_offset = Object::tags_offset() +
       RawObject::kClassIdTagPos / kBitsPerByte;
   ldrh(result, FieldAddress(object, class_id_offset), cond);
 }
 
 
 void Assembler::LoadClassById(Register result, Register class_id) {
   ASSERT(result != class_id);
-  LoadImmediate(result, Isolate::Current()->class_table()->TableAddress());
-  LoadFromOffset(kWord, result, result, 0);
+  LoadIsolate(result);
+  const intptr_t offset =
+      Isolate::class_table_offset() + ClassTable::table_offset();
+  LoadFromOffset(kWord, result, result, offset);
   ldr(result, Address(result, class_id, LSL, 2));
 }
 
 
 void Assembler::LoadClass(Register result, Register object, Register scratch) {
   ASSERT(scratch != result);
   LoadClassId(scratch, object);
   LoadClassById(result, scratch);
 }
 
@@ skipping 1646 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfFpuRegisters));
   return fpu_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM