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

src/ppc/codegen-ppc.cc

Index: src/ppc/codegen-ppc.cc
diff --git a/src/ppc/codegen-ppc.cc b/src/ppc/codegen-ppc.cc
index 412942bad576098277686abea37e49843bb9c53c..d88b589f2d0bdd479b6dd63c674a59feb6c7ad8c 100644
--- a/src/ppc/codegen-ppc.cc
+++ b/src/ppc/codegen-ppc.cc
@@ -74,16 +74,16 @@ UnaryMathFunctionWithIsolate CreateExpFunction(Isolate* isolate) {
 }
 
 
-UnaryMathFunction CreateSqrtFunction() {
+UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
 #if defined(USE_SIMULATOR)
-  return &std::sqrt;
+  return nullptr;
 #else
   size_t actual_size;
   byte* buffer =
       static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
-  if (buffer == NULL) return &std::sqrt;
+  if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size),
+  MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
                       CodeObjectRequired::kNo);
 
 // Called from C
@@ -100,9 +100,9 @@ UnaryMathFunction CreateSqrtFunction() {
   DCHECK(!RelocInfo::RequiresRelocation(desc));
 #endif
 
-  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);
 #endif
 }