Made vararg parameters have Array<out T> type

instead of simply Array<T>
  #KT-1638 Fixed
  #KT-2163 Fixed
  #KT-3213 Fixed
  #KT-4172 Fixed
  #KT-5534 Fixed

compiler/testData/diagnostics/tests/inference/mapFunction.kt

@@ -25,7 +25,7 @@ fun foo() {
 // ---------------------
 // copy from kotlin util
 
-fun <T> array(vararg t : T) : Array<T> = t
+fun <T> array(vararg t : T) : Array<T> = t as Array<T>
 
 fun <T, R> Array<T>.map(<!UNUSED_PARAMETER!>transform<!> : (T) -> R) : List<R> {<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>