Fix tests not to duplicate array constructor definitions as they are available now in builtins.

compiler/testData/diagnostics/tests/regressions/kt312.kt

@@ -1,6 +1,3 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
-public inline fun <reified T> Array(n: Int, block: (Int) -> T): Array<T> = null!!
-
 // KT-312 Nullability problem when a nullable version of a generic type is returned
 
 fun <T> Array<out T>.safeGet(index : Int) : T? {

compiler/testData/diagnostics/tests/regressions/kt312.txt

@@ -3,5 +3,4 @@ package
 public val args: kotlin.Array<kotlin.String>
 public val name: kotlin.String
 public val name1: kotlin.String?
-public inline fun </*0*/ reified T> Array(/*0*/ n: kotlin.Int, /*1*/ block: (kotlin.Int) -> T): kotlin.Array<T>
 public fun </*0*/ T> kotlin.Array<out T>.safeGet(/*0*/ index: kotlin.Int): T?