Do not call mkdirs when destination file of copyTo doesn't have any parent directory.

#KT-7888 Fixed

libraries/stdlib/src/kotlin/io/files/Utils.kt

@@ -218,7 +218,7 @@ public fun File.copyTo(dst: File, overwrite: Boolean = false, bufferSize: Int =
             return copyTo(dst.resolve(name), overwrite, bufferSize)
         }
     }
-    dst.getParentFile().mkdirs()
+    dst.getParentFile()?.mkdirs()
     dst.delete()
     val input = FileInputStream(this)
     return input.use<FileInputStream, Long> {

libraries/stdlib/test/io/Files.kt

@@ -780,6 +780,26 @@ class FilesTest {
         srcFile.delete()
     }
 
+    test fun copyToNameWithoutParent() {
+        val currentDir = File("").getAbsoluteFile()!!
+        val srcFile = createTempFile()
+        val dstFile = createTempFile(directory = currentDir)
+        try {
+            srcFile.writeText("Hello, World!", "UTF8")
+            dstFile.delete()
+
+            val dstRelative = File(dstFile.name)
+
+            srcFile.copyTo(dstRelative)
+
+            assertEquals(srcFile.readText(), dstFile.readText())
+        }
+        finally {
+            dstFile.delete()
+            srcFile.delete()
+        }
+    }
+
     test fun deleteRecursively() {
         val dir = createTempDir()
         dir.delete()