Call JS functions via native context instead of js builtins object.

src/full-codegen/mips/full-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_MIPS
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 4535 matching lines @@
   ExternalReference debug_is_active =
       ExternalReference::debug_is_active_address(isolate());
   __ li(at, Operand(debug_is_active));
   __ lb(v0, MemOperand(at));
   __ SmiTag(v0);
   context()->Plug(v0);
 }
 
 
 void FullCodeGenerator::EmitLoadJSRuntimeFunction(CallRuntime* expr) {
-  // Push the builtins object as the receiver.
-  Register receiver = LoadDescriptor::ReceiverRegister();
-  __ lw(receiver, GlobalObjectOperand());
-  __ lw(receiver, FieldMemOperand(receiver, GlobalObject::kBuiltinsOffset));
-  __ push(receiver);
+  // Push undefined as the receiver.
+  __ LoadRoot(v0, Heap::kUndefinedValueRootIndex);
+  __ push(v0);
 
-  // Load the function from the receiver.
-  __ li(LoadDescriptor::NameRegister(), Operand(expr->name()));
-  __ li(LoadDescriptor::SlotRegister(),
-        Operand(SmiFromSlot(expr->CallRuntimeFeedbackSlot())));
-  CallLoadIC(NOT_INSIDE_TYPEOF);
+  __ lw(v0, GlobalObjectOperand());
+  __ lw(v0, FieldMemOperand(v0, GlobalObject::kNativeContextOffset));
+  __ lw(v0, ContextOperand(v0, expr->context_index()));
 }
 
 
 void FullCodeGenerator::EmitCallJSRuntimeFunction(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
 
   SetCallPosition(expr, arg_count);
   CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
   __ lw(a1, MemOperand(sp, (arg_count + 1) * kPointerSize));
@@ skipping 801 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS