MIPS: Convert UnaryOpStub to a HydrogenCodeStub.

src/mips/full-codegen-mips.cc

Index: src/mips/full-codegen-mips.cc
diff --git a/src/mips/full-codegen-mips.cc b/src/mips/full-codegen-mips.cc
index 032c1f5e5bc3aacc80d415349a5a90192b0f7a1c..43325dfb2ca12f7199bc716834dc0b6c232f8a1a 100644
--- a/src/mips/full-codegen-mips.cc
+++ b/src/mips/full-codegen-mips.cc
@@ -4400,10 +4400,7 @@ void FullCodeGenerator::EmitUnaryOperation(UnaryOperation* expr,
                                            const char* comment) {
   // TODO(svenpanne): Allowing format strings in Comment would be nice here...
   Comment cmt(masm_, comment);
-  bool can_overwrite = expr->expression()->ResultOverwriteAllowed();
-  UnaryOverwriteMode overwrite =
-      can_overwrite ? UNARY_OVERWRITE : UNARY_NO_OVERWRITE;
-  UnaryOpStub stub(expr->op(), overwrite);
+  UnaryOpStub stub(expr->op());
   // GenericUnaryOpStub expects the argument to be in a0.
   VisitForAccumulatorValue(expr->expression());
   SetSourcePosition(expr->position());