Revert r6543 and r6441.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
===================================================================
--- src/x64/lithium-x64.cc	(revision 6473)
+++ src/x64/lithium-x64.cc	(working copy)
@@ -651,6 +651,22 @@
 }
 
 
+LInstruction* LChunkBuilder::SetInstructionPendingDeoptimizationEnvironment(
+    LInstruction* instr, int ast_id) {
+  ASSERT(instructions_pending_deoptimization_environment_ == NULL);
+  ASSERT(pending_deoptimization_ast_id_ == AstNode::kNoNumber);
+  instructions_pending_deoptimization_environment_ = instr;
+  pending_deoptimization_ast_id_ = ast_id;
+  return instr;
+}
+
+
+void LChunkBuilder::ClearInstructionPendingDeoptimizationEnvironment() {
+  instructions_pending_deoptimization_environment_ = NULL;
+  pending_deoptimization_ast_id_ = AstNode::kNoNumber;
+}
+
+
 LInstruction* LChunkBuilder::MarkAsCall(LInstruction* instr,
                                         HInstruction* hinstr,
                                         CanDeoptimize can_deoptimize) {
@@ -660,8 +676,8 @@
   if (hinstr->HasSideEffects()) {
     ASSERT(hinstr->next()->IsSimulate());
     HSimulate* sim = HSimulate::cast(hinstr->next());
-    ASSERT(pending_deoptimization_ast_id_ == AstNode::kNoNumber);
-    pending_deoptimization_ast_id_ = sim->ast_id();
+    instr = SetInstructionPendingDeoptimizationEnvironment(
+        instr, sim->ast_id());
   }
 
   // If instruction does not have side-effects lazy deoptimization
@@ -1625,11 +1641,12 @@
 
   // If there is an instruction pending deoptimization environment create a
   // lazy bailout instruction to capture the environment.
-  if (pending_deoptimization_ast_id_ != AstNode::kNoNumber) {
-    ASSERT(pending_deoptimization_ast_id_ == instr->ast_id());
+  if (pending_deoptimization_ast_id_ == instr->ast_id()) {
     LLazyBailout* lazy_bailout = new LLazyBailout;
     LInstruction* result = AssignEnvironment(lazy_bailout);
-    pending_deoptimization_ast_id_ = AstNode::kNoNumber;
+    instructions_pending_deoptimization_environment_->
+        set_deoptimization_environment(result->environment());
+    ClearInstructionPendingDeoptimizationEnvironment();
     return result;
   }