Reland "Fixed environment assignment for LCheckNonSmi."

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 97722ccfa24876d8671978cbabfc49f5ce8fab64..357c191d817dd209487ff01bbaba11fee55f7761 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -1963,7 +1963,9 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
 
 LInstruction* LChunkBuilder::DoCheckHeapObject(HCheckHeapObject* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
-  return AssignEnvironment(new(zone()) LCheckNonSmi(value));
+  LInstruction* result = new(zone()) LCheckNonSmi(value);
+  if (!instr->value()->IsHeapObject()) result = AssignEnvironment(result);
+  return result;
 }