fix mingw constructor

Author: archinamon

src/mingwX64Main/kotlin/File.kt

@@ -7,12 +7,10 @@ import platform.windows.*
 private const val EPOCH_DIFF = 11644473600000
 
 
-actual class File {
+actual class File actual constructor(pathname: String) {
 
     private val pathname: String = pathname.replace('/', filePathSeparator)
 
-    actual constructor(pathname: String)
-
     actual fun getParent(): String? {
         return if (exists()) getAbsolutePath().substringBeforeLast(filePathSeparator) else null
     }