Remove unnecessary explicity prototype check.

src/arm/stub-cache-arm.cc

Index: src/arm/stub-cache-arm.cc
diff --git a/src/arm/stub-cache-arm.cc b/src/arm/stub-cache-arm.cc
index f2d45e190af4679ee81638192e871e8e230b4d78..676fa0f5ea743889644c2fd26411fb4e354989ec 100644
--- a/src/arm/stub-cache-arm.cc
+++ b/src/arm/stub-cache-arm.cc
@@ -1225,7 +1225,7 @@ void BaseLoadStubCompiler::NonexistentHandlerFrontend(
     Handle<GlobalObject> global) {
   Label miss;
 
-  Register reg = HandlerFrontendHeader(object, receiver(), last, name, &miss);
+  HandlerFrontendHeader(object, receiver(), last, name, &miss);
 
   // If the last object in the prototype chain is a global object,
   // check that the global property cell is empty.
@@ -1233,13 +1233,6 @@ void BaseLoadStubCompiler::NonexistentHandlerFrontend(
     GenerateCheckPropertyCell(masm(), global, name, scratch2(), &miss);
   }
 
-  if (!last->HasFastProperties()) {
-    __ ldr(scratch2(), FieldMemOperand(reg, HeapObject::kMapOffset));
-    __ ldr(scratch2(), FieldMemOperand(scratch2(), Map::kPrototypeOffset));
-    __ cmp(scratch2(), Operand(isolate()->factory()->null_value()));
-    __ b(ne, &miss);
-  }
-
   HandlerFrontendFooter(success, &miss);
 }