Remove unnecessary explicity prototype check.

src/mips/stub-cache-mips.cc

Index: src/mips/stub-cache-mips.cc
diff --git a/src/mips/stub-cache-mips.cc b/src/mips/stub-cache-mips.cc
index da6770a14ce05e5095558c4110b61a1c5f92a529..b6bf924b6600877d6170ee271365bea259b22ff2 100644
--- a/src/mips/stub-cache-mips.cc
+++ b/src/mips/stub-cache-mips.cc
@@ -1229,7 +1229,7 @@ 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.
@@ -1237,13 +1237,6 @@ void BaseLoadStubCompiler::NonexistentHandlerFrontend(
     GenerateCheckPropertyCell(masm(), global, name, scratch2(), &miss);
   }
 
-  if (!last->HasFastProperties()) {
-    __ lw(scratch2(), FieldMemOperand(reg, HeapObject::kMapOffset));
-    __ lw(scratch2(), FieldMemOperand(scratch2(), Map::kPrototypeOffset));
-    __ Branch(&miss, ne, scratch2(),
-        Operand(isolate()->factory()->null_value()));
-  }
-
   HandlerFrontendFooter(success, &miss);
 }