[compiler] Drop the CompareNilIC.

src/crankshaft/hydrogen-types.cc

Index: src/crankshaft/hydrogen-types.cc
diff --git a/src/crankshaft/hydrogen-types.cc b/src/crankshaft/hydrogen-types.cc
index 8c8562581a1d1cc5d38241764e86e9ff1a25b4bc..ab27f01257ede2d20e39f6191295119acfc2244d 100644
--- a/src/crankshaft/hydrogen-types.cc
+++ b/src/crankshaft/hydrogen-types.cc
@@ -22,7 +22,7 @@ HType HType::FromType(Type* type) {
   if (type->Is(Type::Boolean())) return HType::Boolean();
   if (type->Is(Type::Undefined())) return HType::Undefined();
   if (type->Is(Type::Object())) return HType::JSObject();
-  if (type->Is(Type::Receiver())) return HType::JSReceiver();
+  if (type->Is(Type::DetectableReceiver())) return HType::JSReceiver();
   return HType::Tagged();
 }
 
@@ -43,8 +43,12 @@ HType HType::FromValue(Handle<Object> value) {
   if (value->IsString()) return HType::String();
   if (value->IsBoolean()) return HType::Boolean();
   if (value->IsUndefined()) return HType::Undefined();
-  if (value->IsJSArray()) return HType::JSArray();
-  if (value->IsJSObject()) return HType::JSObject();
+  if (value->IsJSArray() && !value->IsUndetectableObject()) {

[Toon Verwaest, 2016/02/23 20:03:19]

JSArrays cannot be undetectable I think. It's only settable on ObjectTemplates
which cannot result in JSArray objects.

[Benedikt Meurer, 2016/02/24 05:39:18]

Done.

+    return HType::JSArray();
+  }
+  if (value->IsJSObject() && !value->IsUndetectableObject()) {
+    return HType::JSObject();
+  }
   DCHECK(value->IsHeapObject());
   return HType::HeapObject();
 }