Version 3.5.6.

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 4d5f60aa7d5bb46f4c4628510b26a1e5ee6aee27..9d08d37626b2ba14055d4ed83d1dee2b2e5062a6 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1519,8 +1519,9 @@ LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) {
 
 
 LInstruction* LChunkBuilder::DoBoundsCheck(HBoundsCheck* instr) {
-  return AssignEnvironment(new LBoundsCheck(UseRegisterAtStart(instr->index()),
-                                            Use(instr->length())));
+  return AssignEnvironment(new LBoundsCheck(
+      UseRegisterOrConstantAtStart(instr->index()),
+      Use(instr->length())));
 }
 
 
@@ -1819,9 +1820,9 @@ LInstruction* LChunkBuilder::DoLoadKeyedFastElement(
   ASSERT(instr->representation().IsTagged());
   ASSERT(instr->key()->representation().IsInteger32());
   LOperand* obj = UseRegisterAtStart(instr->object());
-  LOperand* key = UseRegisterAtStart(instr->key());
+  LOperand* key = UseRegisterOrConstantAtStart(instr->key());
   LLoadKeyedFastElement* result = new LLoadKeyedFastElement(obj, key);
-  return AssignEnvironment(DefineSameAsFirst(result));
+  return AssignEnvironment(DefineAsRegister(result));
 }