Revert "Lazy deopt without code patching."

runtime/vm/code_patcher_ia32.cc

 // Copyright (c) 2012, 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"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/cpu.h"
@@ skipping 159 matching lines @@
                                     const Code& code,
                                     const Code& new_target) {
   const Instructions& instrs = Instructions::Handle(code.instructions());
   WritableInstructionsScope writable(instrs.PayloadStart(), instrs.size());
   ASSERT(code.ContainsInstructionAt(return_address));
   StaticCall call(return_address);
   call.set_target(new_target);
 }
 
 
-void CodePatcher::InsertDeoptimizationCallAt(uword start) {
-  UNREACHABLE();
+void CodePatcher::InsertDeoptimizationCallAt(uword start, uword target) {
+  // The inserted call should not overlap the lazy deopt jump code.
+  ASSERT(start + CallPattern::pattern_length_in_bytes() <= target);
+  *reinterpret_cast<uint8_t*>(start) = 0xE8;
+  CallPattern call(start);
+  call.SetTargetAddress(target);
+  CPU::FlushICache(start, CallPattern::pattern_length_in_bytes());
 }
 
 
 RawCode* CodePatcher::GetInstanceCallAt(
     uword return_address, const Code& code, ICData* ic_data) {
   ASSERT(code.ContainsInstructionAt(return_address));
   InstanceCall call(return_address);
   if (ic_data != NULL) {
     *ic_data ^= call.ic_data();
   }
@@ skipping 56 matching lines @@
 
 
 
 intptr_t CodePatcher::InstanceCallSizeInBytes() {
   return InstanceCall::kPatternSize;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32