Fix build failure on Windows since r14116.

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index 941f34d577ee70ea2cc77f21e9a26cf8de08cf72..b57e3907ce9eee32940038e6aaf9d7dd2935cadf 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -907,12 +907,6 @@ Handle<Value> Shell::Uint8ClampedArray(const Arguments& args) {
 }
 
 
-Handle<Value> Shell::Yield(const Arguments& args) {
-  v8::Unlocker unlocker(args.GetIsolate());
-  return Undefined(args.GetIsolate());
-}
-
-
 Handle<Value> Shell::Quit(const Arguments& args) {
   int exit_code = args[0]->Int32Value();
   OnExit();