IR: move KotlnMangler to ir.tree module

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/KotlinMangler.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2010-2019 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.ir.util
+
+import org.jetbrains.kotlin.ir.declarations.IrDeclaration
+import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.name.Name
+
+interface KotlinMangler {
+    val String.hashMangle: Long
+    val IrDeclaration.hashedMangle: Long
+    fun IrDeclaration.isExported(): Boolean
+    val IrFunction.functionName: String
+    val IrType.isInlined: Boolean
+    val Long.isSpecial: Boolean
+
+    companion object {
+        private val FUNCTION_PREFIX = "<BUILT-IN-FUNCTION>"
+        fun functionClassSymbolName(name: Name) = "ktype:$FUNCTION_PREFIX$name"
+        fun functionInvokeSymbolName(name: Name) = "kfun:$FUNCTION_PREFIX$name.invoke"
+    }
+}