Remove all uses of field-tracking flags that do not make decisions but are subject to existing info…

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 d42d3824e2f37d2b9ee94888e0d4c8bbcc8eb286..fa3954cda47dfdfa5a97d5f0fb7a14e9d8056a2f 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -2128,7 +2128,7 @@ LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
 
   bool can_be_constant = instr->value()->IsConstant() &&
       HConstant::cast(instr->value())->NotInNewSpace() &&
-      !(FLAG_track_double_fields && instr->field_representation().IsDouble());
+      !instr->field_representation().IsDouble();
 
   LOperand* val;
   if (needs_write_barrier) {
@@ -2137,10 +2137,9 @@ LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
     val = UseFixed(instr->value(), rax);
   } else if (can_be_constant) {
     val = UseRegisterOrConstant(instr->value());
-  } else if (FLAG_track_fields && instr->field_representation().IsSmi()) {
+  } else if (instr->field_representation().IsSmi()) {
     val = UseRegister(instr->value());
-  } else if (FLAG_track_double_fields &&
-             instr->field_representation().IsDouble()) {
+  } else if (instr->field_representation().IsDouble()) {
     val = UseRegisterAtStart(instr->value());
   } else {
     val = UseRegister(instr->value());
@@ -2152,8 +2151,7 @@ LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
       needs_write_barrier_for_map) ? TempRegister() : NULL;
 
   LStoreNamedField* result = new(zone()) LStoreNamedField(obj, val, temp);
-  if (FLAG_track_heap_object_fields &&
-      instr->field_representation().IsHeapObject()) {
+  if (instr->field_representation().IsHeapObject()) {
     if (!instr->value()->type().IsHeapObject()) {
       return AssignEnvironment(result);
     }