[turbofan] Fix register constraint for memory barrier.

src/compiler/x64/instruction-selector-x64.cc

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index 172219d11dc7774b4b36a8a1c0d343c05595f44a..cdd2b052eadf68cca0bb0fad1527945cdb384a37 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -189,9 +189,7 @@ 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: