Eliminates some branches from arm code.

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"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 1628 matching lines @@
                                          const Address& dest,
                                          const Object& value) {
   ASSERT(value.IsSmi() || value.InVMHeap() ||
          (value.IsOld() && value.IsNotTemporaryScopedHandle()));
   // No store buffer update.
   LoadObject(IP, value);
   str(IP, dest);
 }
 
 
-void Assembler::LoadClassId(Register result, Register object) {
+void Assembler::LoadClassId(Register result, Register object, Condition cond) {
   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));
+  ldrh(result, FieldAddress(object, class_id_offset), cond);
 }
 
 
 void Assembler::LoadClassById(Register result, Register class_id) {
   ASSERT(result != class_id);
   ldr(result, FieldAddress(CTX, Context::isolate_offset()));
   const intptr_t table_offset_in_isolate =
       Isolate::class_table_offset() + ClassTable::table_offset();
   LoadFromOffset(kWord, result, result, table_offset_in_isolate);
   ldr(result, Address(result, class_id, LSL, 2));
@@ skipping 1526 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