Always set the callee's context when calling a function from optimized code.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2889 matching lines @@
       function->shared()->formal_parameter_count() == arity;
 
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
 
   if (can_invoke_directly) {
     if (a1_state == A1_UNINITIALIZED) {
       __ LoadHeapObject(a1, function);
     }
 
-    // Change context if needed.
-    bool change_context =
-        (info()->closure()->context() != function->context()) ||
-        scope()->contains_with() ||
-        (scope()->num_heap_slots() > 0);
-    if (change_context) {
-      __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
-    }
+    // Change context.
+    __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
 
     // Set r0 to arguments count if adaption is not needed. Assumes that r0
     // is available to write to at this point.
     if (!function->NeedsArgumentsAdaption()) {
       __ li(a0, Operand(arity));
     }
 
     // Invoke function.
     __ SetCallKind(t1, call_kind);
     __ lw(at, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
@@ skipping 2279 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal