Cleaned up CpuFeature scope handling.

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 5f467e3ceea049bd7e8ef286c0419a9b57badc3b..a784677a9e092f972b7ddba6fe3662224288524e 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -898,7 +898,7 @@ void MacroAssembler::PushCallerSaved(SaveFPRegsMode fp_mode,
   }
   // R12 to r15 are callee save on all platforms.
   if (fp_mode == kSaveFPRegs) {
-    CpuFeatures::Scope scope(SSE2);
+    CpuFeatureScope scope(this, SSE2);
     subq(rsp, Immediate(kDoubleSize * XMMRegister::kMaxNumRegisters));
     for (int i = 0; i < XMMRegister::kMaxNumRegisters; i++) {
       XMMRegister reg = XMMRegister::from_code(i);
@@ -913,7 +913,7 @@ void MacroAssembler::PopCallerSaved(SaveFPRegsMode fp_mode,
                                     Register exclusion2,
                                     Register exclusion3) {
   if (fp_mode == kSaveFPRegs) {
-    CpuFeatures::Scope scope(SSE2);
+    CpuFeatureScope scope(this, SSE2);
     for (int i = 0; i < XMMRegister::kMaxNumRegisters; i++) {
       XMMRegister reg = XMMRegister::from_code(i);
       movsd(reg, Operand(rsp, i * kDoubleSize));