Decouple CpuFeatures from serializer state.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 14c3fa976bb6a0d91f2aae73b12c160fa94433bf..48c080dcdc61aa72424a2ba58fc683564700c6e2 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -60,7 +60,7 @@ int64_t MacroAssembler::RootRegisterDelta(ExternalReference other) {
 
 Operand MacroAssembler::ExternalOperand(ExternalReference target,
                                         Register scratch) {
-  if (root_array_available_ && !Serializer::enabled(isolate())) {
+  if (root_array_available_ && !serializer_enabled()) {
     int64_t delta = RootRegisterDelta(target);
     if (delta != kInvalidRootRegisterDelta && is_int32(delta)) {
       return Operand(kRootRegister, static_cast<int32_t>(delta));
@@ -72,7 +72,7 @@ Operand MacroAssembler::ExternalOperand(ExternalReference target,
 
 
 void MacroAssembler::Load(Register destination, ExternalReference source) {
-  if (root_array_available_ && !Serializer::enabled(isolate())) {
+  if (root_array_available_ && !serializer_enabled()) {
     int64_t delta = RootRegisterDelta(source);
     if (delta != kInvalidRootRegisterDelta && is_int32(delta)) {
       movp(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
@@ -90,7 +90,7 @@ void MacroAssembler::Load(Register destination, ExternalReference source) {
 
 
 void MacroAssembler::Store(ExternalReference destination, Register source) {
-  if (root_array_available_ && !Serializer::enabled(isolate())) {
+  if (root_array_available_ && !serializer_enabled()) {
     int64_t delta = RootRegisterDelta(destination);
     if (delta != kInvalidRootRegisterDelta && is_int32(delta)) {
       movp(Operand(kRootRegister, static_cast<int32_t>(delta)), source);
@@ -109,7 +109,7 @@ void MacroAssembler::Store(ExternalReference destination, Register source) {
 
 void MacroAssembler::LoadAddress(Register destination,
                                  ExternalReference source) {
-  if (root_array_available_ && !Serializer::enabled(isolate())) {
+  if (root_array_available_ && !serializer_enabled()) {
     int64_t delta = RootRegisterDelta(source);
     if (delta != kInvalidRootRegisterDelta && is_int32(delta)) {
       leap(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
@@ -122,7 +122,7 @@ void MacroAssembler::LoadAddress(Register destination,
 
 
 int MacroAssembler::LoadAddressSize(ExternalReference source) {
-  if (root_array_available_ && !Serializer::enabled(isolate())) {
+  if (root_array_available_ && !serializer_enabled()) {
     // This calculation depends on the internals of LoadAddress.
     // It's correctness is ensured by the asserts in the Call
     // instruction below.
@@ -144,7 +144,7 @@ int MacroAssembler::LoadAddressSize(ExternalReference source) {
 
 void MacroAssembler::PushAddress(ExternalReference source) {
   int64_t address = reinterpret_cast<int64_t>(source.address());
-  if (is_int32(address) && !Serializer::enabled(isolate())) {
+  if (is_int32(address) && !serializer_enabled()) {
     if (emit_debug_code()) {
       Move(kScratchRegister, kZapValue, Assembler::RelocInfoNone());
     }
@@ -252,7 +252,7 @@ void MacroAssembler::InNewSpace(Register object,
                                 Condition cc,
                                 Label* branch,
                                 Label::Distance distance) {
-  if (Serializer::enabled(isolate())) {
+  if (serializer_enabled()) {
     // Can't do arithmetic on external references if it might get serialized.
     // The mask isn't really an address.  We load it as an external reference in
     // case the size of the new space is different between the snapshot maker