[turbofan] Fix register constraint for memory barrier.

src/compiler/mips/instruction-selector-mips.cc

 // Copyright 2014 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/base/adapters.h"
 #include "src/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 176 matching lines @@
   WriteBarrierKind write_barrier_kind = store_rep.write_barrier_kind();
   MachineRepresentation rep = store_rep.representation();
 
   // TODO(mips): I guess this could be done in a better way.
   if (write_barrier_kind != kNoWriteBarrier) {
     DCHECK_EQ(MachineRepresentation::kTagged, rep);
     InstructionOperand inputs[3];
     size_t input_count = 0;
     inputs[input_count++] = g.UseUniqueRegister(base);
     inputs[input_count++] = g.UseUniqueRegister(index);
-    inputs[input_count++] = (write_barrier_kind == kMapWriteBarrier)
-                                ? g.UseRegister(value)
-                                : g.UseUniqueRegister(value);
+    inputs[input_count++] = g.UseUniqueRegister(value);
     RecordWriteMode record_write_mode = RecordWriteMode::kValueIsAny;
     switch (write_barrier_kind) {
       case kNoWriteBarrier:
         UNREACHABLE();
         break;
       case kMapWriteBarrier:
         record_write_mode = RecordWriteMode::kValueIsMap;
         break;
       case kPointerWriteBarrier:
         record_write_mode = RecordWriteMode::kValueIsPointer;
@@ skipping 1180 matching lines @@
          MachineOperatorBuilder::kFloat32Max |
          MachineOperatorBuilder::kFloat32RoundDown |
          MachineOperatorBuilder::kFloat32RoundUp |
          MachineOperatorBuilder::kFloat32RoundTruncate |
          MachineOperatorBuilder::kFloat32RoundTiesEven;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8