Improve handling of unary plus.

src/arm/full-codegen-arm.cc

Index: src/arm/full-codegen-arm.cc
diff --git a/src/arm/full-codegen-arm.cc b/src/arm/full-codegen-arm.cc
index ba0f141289254bb0f4d212863473096c17b6b038..6a332340315926960540a946599a398d1d3ce979 100644
--- a/src/arm/full-codegen-arm.cc
+++ b/src/arm/full-codegen-arm.cc
@@ -3976,18 +3976,6 @@ void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
       break;
     }
 
-    case Token::ADD: {
-      Comment cmt(masm_, "[ UnaryOperation (ADD)");
-      VisitForAccumulatorValue(expr->expression());
-      Label no_conversion;
-      __ JumpIfSmi(result_register(), &no_conversion);
-      ToNumberStub convert_stub;
-      __ CallStub(&convert_stub);
-      __ bind(&no_conversion);
-      context()->Plug(result_register());
-      break;
-    }
-
     case Token::SUB:
       EmitUnaryOperation(expr, "[ UnaryOperation (SUB)");
       break;