Allow eval in detached contexts

BUG=

Review URL: https://codereview.chromium.org/781953002

Cr-Commit-Position: refs/heads/master@{#25686}

src/runtime/runtime-object.cc

@@ -1368,16 +1368,6 @@ RUNTIME_FUNCTION(Runtime_GlobalProxy) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_IsAttachedGlobal) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_CHECKED(Object, global, 0);
-  if (!global->IsJSGlobalObject()) return isolate->heap()->false_value();
-  return isolate->heap()->ToBoolean(
-      !JSGlobalObject::cast(global)->IsDetached());
-}
-
-
 RUNTIME_FUNCTION(Runtime_LookupAccessor) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3);

src/runtime/runtime.h

@@ -254,7 +254,6 @@ namespace internal {
                                                        \
   /* Eval */                                           \
   F(GlobalProxy, 1, 1)                                 \
-  F(IsAttachedGlobal, 1, 1)                            \
                                                        \
   F(AddNamedProperty, 4, 1)                            \
   F(AddPropertyForTemplate, 4, 1)                      \

src/v8natives.js

@@ -163,16 +163,6 @@ function GlobalParseFloat(string) {
 function GlobalEval(x) {
   if (!IS_STRING(x)) return x;
 
-  // For consistency with JSC we require the global object passed to
-  // eval to be the global object from which 'eval' originated. This
-  // is not mandated by the spec.
-  // We only throw if the global has been detached, since we need the
-  // receiver as this-value for the call.
-  if (!%IsAttachedGlobal(global)) {
-    throw new $EvalError('The "this" value passed to eval must ' +
-                         'be the global object from which eval originated');
-  }
-
   var global_proxy = %GlobalProxy(global);
 
   var f = %CompileString(x, false, 0);

test/cctest/test-api.cc

@@ -11549,8 +11549,7 @@ THREADED_TEST(CrossEval) {
 
 
 // Test that calling eval in a context which has been detached from
-// its global throws an exception.  This behavior is consistent with
-// other JavaScript implementations.
+// its global proxy works.
 THREADED_TEST(EvalInDetachedGlobal) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);
@@ -11578,8 +11577,7 @@ THREADED_TEST(EvalInDetachedGlobal) {
   context0->DetachGlobal();
   v8::TryCatch catcher;
   x_value = CompileRun("fun('x')");
-  CHECK(x_value.IsEmpty());
-  CHECK(catcher.HasCaught());
+  CHECK_EQ(42, x_value->Int32Value());
   context1->Exit();
 }