Eliminate map checks of constant values.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index d12b229c381323ca0f80f417548b6e29e90e9403..18121821671d58bb762480df85fe175022583d37 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -5230,6 +5230,7 @@ void LCodeGen::DoCheckMapCommon(Register map_reg,
 
 
 void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
+  if (instr->hydrogen()->CanOmitMapChecks()) return;
   Register map_reg = scratch0();
   LOperand* input = instr->value();
   ASSERT(input->IsRegister());
@@ -5302,6 +5303,8 @@ void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
 
 
 void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
+  if (instr->hydrogen()->CanOmitPrototypeChecks()) return;
+
   Register prototype_reg = ToRegister(instr->temp());
   Register map_reg = ToRegister(instr->temp2());
 
@@ -5310,12 +5313,10 @@ void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
 
   ASSERT(prototypes->length() == maps->length());
 
-  if (!instr->hydrogen()->CanOmitPrototypeChecks()) {
-    for (int i = 0; i < prototypes->length(); i++) {
-      __ LoadHeapObject(prototype_reg, prototypes->at(i));
-      __ ldr(map_reg, FieldMemOperand(prototype_reg, HeapObject::kMapOffset));
-      DoCheckMapCommon(map_reg, maps->at(i), instr->environment());
-    }
+  for (int i = 0; i < prototypes->length(); i++) {
+    __ LoadHeapObject(prototype_reg, prototypes->at(i));
+    __ ldr(map_reg, FieldMemOperand(prototype_reg, HeapObject::kMapOffset));
+    DoCheckMapCommon(map_reg, maps->at(i), instr->environment());
   }
 }