Extract module 'config' out of 'frontend'

Also move deprecated TargetPlatform there. This allows to get rid of the
dependency cli.common -> frontend, and even on frontend.common.

compiler/frontend.common/src/org/jetbrains/kotlin/resolve/TargetPlatform.kt

@@ -1,15 +0,0 @@
-/*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.resolve
-
-@Deprecated(
-    message = "This class is deprecated and will be removed soon, use API from 'org.jetbrains.kotlin.platform.*' packages instead",
-    replaceWith = ReplaceWith("TargetPlatform", "org.jetbrains.kotlin.platform.TargetPlatform"),
-    level = DeprecationLevel.ERROR
-)
-interface TargetPlatform {
-    val platformName: String
-}