Added tests for stdlib Array constructors

compiler/testData/codegen/boxWithStdlib/arrays/multiArrayConstructors.kt

@@ -0,0 +1,29 @@
+import kotlin.test.assertEquals
+
+fun stringMultiArray(): Array<Array<String>> = Array(3) {
+    i -> Array(3) { j -> "$i-$j" }
+}
+
+fun stringNullableMultiArray(): Array<Array<String?>> = Array(3) {
+    i -> if (i == 1) Array(3) { j -> "$i-$j" } as Array<String?> else arrayOfNulls<String>(3)
+}
+
+fun box(): String {
+    val matrix = stringMultiArray()
+
+    for (i in 0..2) {
+        for (j in 0..2) {
+            assertEquals("$i-$j", matrix[i][j], "matrix")
+        }
+    }
+
+    val matrixNullable = stringNullableMultiArray()
+
+    for (j in 0..2) {
+        assertEquals(null, matrixNullable[0][j], "nullable")
+        assertEquals("1-$j", matrixNullable[1][j], "nullable")
+        assertEquals(null, matrixNullable[2][j], "nullable")
+    }
+
+    return "OK"
+}