[utils][K/N] Added some util functions to File

compiler/util-io/src/org/jetbrains/kotlin/konan/file/File.kt

@@ -36,7 +36,7 @@ data class File constructor(internal val javaPath: Path) {
         get() = File(canonicalPath)
 
     val name: String
-        get() = javaPath.fileName.toString().removeSuffixIfPresent("/") // https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8153248
+        get() = javaPath.fileName.toString().removeSuffixIfPresent(separator) // https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8153248
     val extension: String
         get() = name.substringAfterLast('.', "")
     val parent: String
@@ -70,6 +70,8 @@ data class File constructor(internal val javaPath: Path) {
         sourcePath.recursiveCopyTo(destPath, resetTimeAttributes = resetTimeAttributes)
     }
 
+    fun renameTo(destination: File) = javaPath.toFile().renameTo(destination.javaPath.toFile())
+
     fun mkdirs() = Files.createDirectories(javaPath)
     fun delete() = Files.deleteIfExists(javaPath)
     fun deleteRecursively() = postorder{Files.delete(it)}
@@ -119,11 +121,13 @@ data class File constructor(internal val javaPath: Path) {
     }
 
     fun deleteOnExit(): File {
-        // Works only on the default file system, 
+        // Works only on the default file system,
         // but that's okay for now.
         javaPath.toFile().deleteOnExit()
         return this // Allow streaming.
     }
+    fun createNew() = javaPath.toFile().createNewFile()
+
     fun readBytes() = Files.readAllBytes(javaPath)
     fun writeBytes(bytes: ByteArray) = Files.write(javaPath, bytes)
     fun appendBytes(bytes: ByteArray)
@@ -135,6 +139,12 @@ data class File constructor(internal val javaPath: Path) {
 
     fun writeText(text: String): Unit = writeLines(listOf(text))
 
+    fun appendLines(lines: Iterable<String>) {
+        Files.write(javaPath, lines, StandardOpenOption.APPEND)
+    }
+
+    fun appendText(text: String): Unit = appendLines(listOf(text))
+
     fun forEachLine(action: (String) -> Unit) {
         Files.lines(javaPath).use { lines ->
             lines.forEach { action(it) }
@@ -167,6 +177,7 @@ data class File constructor(internal val javaPath: Path) {
             get() = File(System.getProperty("java.home"))
         val pathSeparator = java.io.File.pathSeparator
         val separator = java.io.File.separator
+        val separatorChar = java.io.File.separatorChar
     }
 
     fun readStrings() = mutableListOf<String>().also { list -> forEachLine{list.add(it)}}