Hide nativeMemUtils and pointerSize

samples/libcurl/src/main/kotlin/org/konan/libcurl/CUrl.kt

@@ -31,8 +31,7 @@ class CUrl(val url: String)  {
 }
 
 fun CPointer<ByteVar>.toKString(length: Int): String {
-    val bytes = ByteArray(length)
-    nativeMemUtils.getByteArray(pointed, bytes, length)
+    val bytes = this.readBytes(length)
     return kotlin.text.fromUtf8Array(bytes, 0, bytes.size)
 }