Added a version of the v8::HandleScope constructor with an Isolate and use that consistently.

test/cctest/test-assembler-x64.cc

Index: test/cctest/test-assembler-x64.cc
diff --git a/test/cctest/test-assembler-x64.cc b/test/cctest/test-assembler-x64.cc
index af06b013aa3939fdb7100c16357aa4f7f4a0054e..d2ea771588c9ec7313cd41e9b5dba75a49ee44bb 100644
--- a/test/cctest/test-assembler-x64.cc
+++ b/test/cctest/test-assembler-x64.cc
@@ -361,7 +361,8 @@ TEST(OperandRegisterDependency) {
 
 TEST(AssemblerX64LabelChaining) {
   // Test chaining of label usages within instructions (issue 1644).
-  v8::HandleScope scope;
+  InitializeVM();
+  v8::HandleScope scope(env->GetIsolate());
   Assembler assm(Isolate::Current(), NULL, 0);
 
   Label target;
@@ -374,7 +375,7 @@ TEST(AssemblerX64LabelChaining) {
 
 TEST(AssemblerMultiByteNop) {
   InitializeVM();
-  v8::HandleScope scope;
+  v8::HandleScope scope(env->GetIsolate());
   v8::internal::byte buffer[1024];
   Isolate* isolate = Isolate::Current();
   Assembler assm(isolate, buffer, sizeof(buffer));