Add more tests on streams and move relevant code from old iterators tests.

libraries/stdlib/test/collections/IteratorsJVMTest.kt

@@ -17,28 +17,4 @@ class IteratorsJVMTest {
 
         assertEquals(15, sum)
     }
-
-    test fun flatMapAndTakeExtractTheTransformedElements() {
-        fun intToBinaryDigits() = { (i: Int) ->
-            val binary = Integer.toBinaryString(i)!!
-            var index = 0
-            stream<Char> { if (index < binary.length()) binary.get(index++) else null }
-        }
-
-        val expected = arrayListOf(
-                      '0', // fibonacci(0) = 0
-                      '1', // fibonacci(1) = 1
-                      '1', // fibonacci(2) = 1
-                 '1', '0', // fibonacci(3) = 2
-                 '1', '1', // fibonacci(4) = 3
-            '1', '0', '1'  // fibonacci(5) = 5
-        )
-
-        assertEquals(expected, fibonacci().flatMap<Int, Char>(intToBinaryDigits()).take(10).toList())
-    }
-
-    test fun flatMapOnStream() {
-        val result = listOf(1, 2).stream().flatMap<Int, Int> { (0..it).stream() }
-        assertEquals(listOf(0, 1, 0, 1, 2), result.toList())
-    }
 }