Eliminate map checks of constant values.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index aebe26b78560b98a8894ca98fae0a25e4c295eae..20d0a98ebb0ef23c306a64fa213d75de4f3cf371 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -2063,8 +2063,10 @@ LInstruction* LChunkBuilder::DoCheckInstanceType(HCheckInstanceType* instr) {
 
 
 LInstruction* LChunkBuilder::DoCheckPrototypeMaps(HCheckPrototypeMaps* instr) {
-  LUnallocated* temp = TempRegister();
+  LUnallocated* temp = NULL;
+  if (!instr->CanOmitPrototypeChecks()) temp = TempRegister();
   LCheckPrototypeMaps* result = new(zone()) LCheckPrototypeMaps(temp);
+  if (instr->CanOmitPrototypeChecks()) return result;
   return AssignEnvironment(result);
 }
 
@@ -2081,8 +2083,10 @@ LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
 
 
 LInstruction* LChunkBuilder::DoCheckMaps(HCheckMaps* instr) {
-  LOperand* value = UseRegisterAtStart(instr->value());
+  LOperand* value = NULL;
+  if (!instr->CanOmitMapChecks()) value = UseRegisterAtStart(instr->value());
   LCheckMaps* result = new(zone()) LCheckMaps(value);
+  if (instr->CanOmitMapChecks()) return result;
   return AssignEnvironment(result);
 }