[turbofan] Fix register constraint for memory barrier.

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

Index: src/compiler/mips/instruction-selector-mips.cc
diff --git a/src/compiler/mips/instruction-selector-mips.cc b/src/compiler/mips/instruction-selector-mips.cc
index c22845a54740c5ca0284f4b89eab6b8c2989aa66..83dbdf6e426c231584d3911ea1710ae0e7469261 100644
--- a/src/compiler/mips/instruction-selector-mips.cc
+++ b/src/compiler/mips/instruction-selector-mips.cc
@@ -194,9 +194,7 @@ void InstructionSelector::VisitStore(Node* node) {
     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: