Fix name of JS DCE tool

compiler/cli/bin/kotlin-dce-js.bat

@@ -0,0 +1,20 @@
+@echo off
+
+rem Copyright 2010-2015 JetBrains s.r.o.
+rem
+rem Licensed under the Apache License, Version 2.0 (the "License");
+rem you may not use this file except in compliance with the License.
+rem You may obtain a copy of the License at
+rem
+rem http://www.apache.org/licenses/LICENSE-2.0
+rem
+rem Unless required by applicable law or agreed to in writing, software
+rem distributed under the License is distributed on an "AS IS" BASIS,
+rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+rem See the License for the specific language governing permissions and
+rem limitations under the License.
+
+setlocal
+set _KOTLIN_COMPILER=org.jetbrains.kotlin.cli.js.dce.K2JSDce
+
+call %~dps0kotlinc.bat %*