Change the handling of stack check on backward branches

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 138219b49a6f247a0498284a022c39edaf7106a6..3943e96cfb4dfea07f94e27d3483a991ae05496e 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -390,8 +390,7 @@ void LChunk::MarkEmptyBlocks() {
     LLabel* label = LLabel::cast(first_instr);
     if (last_instr->IsGoto()) {
       LGoto* goto_instr = LGoto::cast(last_instr);
-      if (!goto_instr->include_stack_check() &&
-          label->IsRedundant() &&
+      if (label->IsRedundant() &&
           !label->is_loop_header()) {
         bool can_eliminate = true;
         for (int i = first + 1; i < last && can_eliminate; ++i) {
@@ -1038,11 +1037,7 @@ LEnvironment* LChunkBuilder::CreateEnvironment(HEnvironment* hydrogen_env) {
 
 
 LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
-  LGoto* result = new LGoto(instr->FirstSuccessor()->block_id(),
-                            instr->include_stack_check());
-  return (instr->include_stack_check())
-      ? AssignPointerMap(result)
-      : result;
+  return new LGoto(instr->FirstSuccessor()->block_id());
 }
 
 
@@ -2209,7 +2204,12 @@ LInstruction* LChunkBuilder::DoSimulate(HSimulate* instr) {
 
 
 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
-  return MarkAsCall(new LStackCheck, instr);
+  if (instr->is_function_entry()) {
+    return MarkAsCall(new LStackCheck, instr);
+  } else {
+    ASSERT(instr->is_backwards_branch());
+    return AssignEnvironment(AssignPointerMap(new LStackCheck));
+  }
 }