[bigint] Adapt Object::NoSideEffectsToString.

R=jkummerow@chromium.org

Bug: v8:6791
Change-Id: Ia46694ef236abd2fa037491a017eb825aa25162a
Reviewed-on: https://chromium-review.googlesource.com/732981Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48856}

src/objects-inl.h

@@ -265,6 +265,8 @@ bool HeapObject::IsExternalTwoByteString() const {
 
 bool Object::IsNumber() const { return IsSmi() || IsHeapNumber(); }
 
+bool Object::IsNumeric() const { return IsNumber() || IsBigInt(); }
+
 bool HeapObject::IsFiller() const {
   InstanceType instance_type = map()->instance_type();
   return instance_type == FREE_SPACE_TYPE || instance_type == FILLER_TYPE;

src/objects.cc

@@ -324,7 +324,7 @@ Handle<String> Object::NoSideEffectsToString(Isolate* isolate,
                                              Handle<Object> input) {
   DisallowJavascriptExecution no_js(isolate);
 
-  if (input->IsString() || input->IsNumber() || input->IsOddball()) {
+  if (input->IsString() || input->IsNumeric() || input->IsOddball()) {
     return Object::ToString(isolate, input).ToHandleChecked();
   } else if (input->IsFunction()) {
     // -- F u n c t i o n

src/objects.h

@@ -964,7 +964,8 @@ template <class C> inline bool Is(Object* obj);
   V(LayoutDescriptor)       \
   V(HeapObject)             \
   V(Primitive)              \
-  V(Number)
+  V(Number)                 \
+  V(Numeric)
 
 #define HEAP_OBJECT_ORDINARY_TYPE_LIST(V) \
   V(AbstractCode)                         \

test/cctest/test-object.cc

@@ -57,6 +57,7 @@ TEST(NoSideEffectsToString) {
   CheckBoolean(isolate, true, "true");
   CheckBoolean(isolate, false, "false");
   CheckBoolean(isolate, false, "false");
+  CheckObject(isolate, factory->NewBigIntFromInt(42), "42");
   CheckObject(isolate, factory->undefined_value(), "undefined");
   CheckObject(isolate, factory->null_value(), "null");