MIPS64: Fix simulator arguments handling on generated code entry.

src/mips64/builtins-mips64.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.
 
 
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS64
 
@@ skipping 764 matching lines @@
     // Set up the context from the function argument.
     __ ld(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
 
     // Push the function and the receiver onto the stack.
     __ Push(a1, a2);
 
     // Copy arguments to the stack in a loop.
     // a3: argc
     // s0: argv, i.e. points to first arg
     Label loop, entry;
-    // TODO(plind): At least on simulator, argc in a3 is an int32_t with junk
-    //    in upper bits. Should fix the root cause, rather than use below
-    //    workaround to clear upper bits.
-    __ dsll32(a3, a3, 0);  // int32_t -> int64_t.
-    __ dsrl32(a3, a3, 0);
     __ dsll(a4, a3, kPointerSizeLog2);
     __ daddu(a6, s0, a4);
     __ b(&entry);
     __ nop();   // Branch delay slot nop.
     // a6 points past last arg.
     __ bind(&loop);
     __ ld(a4, MemOperand(s0));  // Read next parameter.
     __ daddiu(s0, s0, kPointerSize);
     __ ld(a4, MemOperand(a4));  // Dereference handle.
     __ push(a4);  // Push parameter.
@@ skipping 787 matching lines @@
     __ break_(0xCC);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64