Move LanguageVersionSettings and JvmTarget to module 'util'

To be used from cli-common in the subsequent commits

compiler/frontend.java/src/org/jetbrains/kotlin/config/JvmTarget.kt

@@ -1,28 +0,0 @@
-/*
- * Copyright 2010-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.config
-
-enum class JvmTarget(val string: String) {
-    JVM_1_6("1.6"),
-    JVM_1_8("1.8"),
-    ;
-
-    companion object {
-        @JvmStatic
-        fun fromString(string: String) = values().find { it.string == string }
-    }
-}