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!>}<!>
 

compiler/testData/diagnostics/tests/inference/regressions/kt2200.kt

@@ -11,4 +11,4 @@ fun main(args: Array<String>) {
 }
 
 //from library
-fun <T> array(vararg t : T) : Array<T> = t
+fun <T> array(vararg t : T) : Array<T> = t as Array<T>

compiler/testData/diagnostics/tests/inference/regressions/kt2294.kt

@@ -13,4 +13,4 @@ public fun test()
 
 //--------------------
 
-fun <T> array(vararg t : T) : Array<T> = t
+fun <T> array(vararg t : T) : Array<T> = t as Array<T>

compiler/testData/diagnostics/tests/inference/varargs/varargsAndPair.kt

@@ -1,8 +0,0 @@
-fun foo<T: Any>(vararg <!UNUSED_PARAMETER!>ts<!>: T): T? = null
-
-class Pair<A>(a: A)
-
-fun test() {
-    val v = foo(Pair(1))
-    <!TYPE_MISMATCH!>v<!>: Int // check that it is not error type
-}

compiler/testData/diagnostics/tests/inference/varargs/varargsAndPair.txt

@@ -1,11 +0,0 @@
-package
-
-internal fun </*0*/ T : kotlin.Any> foo(/*0*/ vararg ts: T /*kotlin.Array<T>*/): T?
-internal fun test(): kotlin.Unit
-
-internal final class Pair</*0*/ A> {
-    public constructor Pair</*0*/ A>(/*0*/ a: A)
-    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
-    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
-}