[turbofan] Fix register constraint for memory barrier.

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index 0003f997905e917693157cd98c49b86d04562741..0f6128da9da739abb92b6af279d43ed2586b0f16 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -418,9 +418,7 @@ void InstructionSelector::VisitStore(Node* node) {
       inputs[input_count++] = g.UseUniqueRegister(index);
       addressing_mode = kMode_MRR;
     }
-    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: