Lazily initialize fast_sqrt() and pass an Isolate parameter to it

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index 91b0eb6de57a554a725008246c3aa00b1ab4bdba..edc2d240f24d12e456b8d21fe2b82c75ecd1e0e6 100644
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -71,13 +71,13 @@ UnaryMathFunctionWithIsolate CreateExpFunction(Isolate* isolate) {
 }
 
 
-UnaryMathFunction CreateSqrtFunction() {
+UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   size_t actual_size;
   // Allocate buffer in executable space.
   byte* buffer =
       static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
-  if (buffer == NULL) return &std::sqrt;
-  MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size),
+  if (buffer == nullptr) return nullptr;
+  MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
                       CodeObjectRequired::kNo);
   // esp[1 * kPointerSize]: raw double input
   // esp[0 * kPointerSize]: return address
@@ -95,9 +95,9 @@ UnaryMathFunction CreateSqrtFunction() {
   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);
 }