[turbofan] Fix register constraint for memory barrier.

src/compiler/x87/instruction-selector-x87.cc

Index: src/compiler/x87/instruction-selector-x87.cc
diff --git a/src/compiler/x87/instruction-selector-x87.cc b/src/compiler/x87/instruction-selector-x87.cc
index 79c2f2db9d5b9ce939ae3cfabb3883af1927fbd3..47ca0235b4795b0c4813a9935f7e020ab443ffce 100644
--- a/src/compiler/x87/instruction-selector-x87.cc
+++ b/src/compiler/x87/instruction-selector-x87.cc
@@ -193,9 +193,7 @@ void InstructionSelector::VisitStore(Node* node) {
       inputs[input_count++] = g.UseUniqueRegister(index);
       addressing_mode = kMode_MR1;
     }
-    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: