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

src/arm64/codegen-arm64.cc

Index: src/arm64/codegen-arm64.cc
diff --git a/src/arm64/codegen-arm64.cc b/src/arm64/codegen-arm64.cc
index 59ce8f2f8873bc13df61bd98a968455ba49ee9ad..ca39c0a91f6afd579646188f35fbbc55b8891311 100644
--- a/src/arm64/codegen-arm64.cc
+++ b/src/arm64/codegen-arm64.cc
@@ -75,8 +75,8 @@ UnaryMathFunctionWithIsolate CreateExpFunction(Isolate* isolate) {
 }
 
 
-UnaryMathFunction CreateSqrtFunction() {
-  return &std::sqrt;
+UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+  return nullptr;
 }