Make fast_exp take an Isolate* paramter

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
diff --git a/src/x64/codegen-x64.cc b/src/x64/codegen-x64.cc
index 5c297f1a079ac3b535e152884f37b85dd02e4a23..f7064b790b7a64d462c99f94694b8e1ea700df12 100644
--- a/src/x64/codegen-x64.cc
+++ b/src/x64/codegen-x64.cc
@@ -32,15 +32,14 @@ void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
 #define __ masm.
 
 
-UnaryMathFunction CreateExpFunction() {
-  if (!FLAG_fast_math) return &std::exp;
+UnaryMathFunctionWithIsolate CreateExpFunction(Isolate* isolate) {
   size_t actual_size;
   byte* buffer =
       static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
-  if (buffer == NULL) return &std::exp;
+  if (buffer == nullptr) return nullptr;
   ExternalReference::InitializeMathExpData();
 
-  MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
+  MacroAssembler masm(nullptr, buffer, static_cast<int>(actual_size));
   // xmm0: raw double input.
   XMMRegister input = xmm0;
   XMMRegister result = xmm1;
@@ -58,9 +57,9 @@ UnaryMathFunction CreateExpFunction() {
   masm.GetCode(&desc);
   DCHECK(!RelocInfo::RequiresRelocation(desc));
 
-  Assembler::FlushICacheWithoutIsolate(buffer, actual_size);
+  Assembler::FlushICache(isolate, buffer, actual_size);
   base::OS::ProtectCode(buffer, actual_size);
-  return FUNCTION_CAST<UnaryMathFunction>(buffer);
+  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
 }