KT-2579 Rename Range.minus() to reversed and make it extension

#KT-2579 fixed

libraries/stdlib/src/kotlin/Ranges.kt

@@ -0,0 +1,23 @@
+package kotlin
+
+public val CharRange.reversed: CharRange
+    get() = CharRange(end, if (start < end) -size else size)
+
+public val ByteRange.reversed: ByteRange
+    get() = ByteRange(end, if (start < end) -size else size)
+
+public val ShortRange.reversed: ShortRange
+    get() = ShortRange(end, if (start < end) -size else size)
+
+public val IntRange.reversed: IntRange
+    get() = IntRange(end, if (start < end) -size else size)
+
+public val FloatRange.reversed: FloatRange
+    get() = FloatRange(end, if (start < end) -size else size)
+
+public val LongRange.reversed: LongRange
+    get() = LongRange(end, if (start < end) -size else size)
+
+public val DoubleRange.reversed: DoubleRange
+    get() = DoubleRange(end, if (start < end) -size else size)
+

libraries/stdlib/test/language/RangeTest.kt

@@ -23,4 +23,23 @@ class RangeTest {
         assertTrue(range.contains(9))
         assertFalse(range.contains(10))
     }
+
+    test fun reversedRanges() {
+        val intRange = 0..9
+        val reversedIntRange = intRange.reversed
+        assertEquals(10, reversedIntRange.size)
+        assertEquals(9, reversedIntRange.start)
+        assertEquals(0, reversedIntRange.end)
+        assertEquals(intRange, reversedIntRange.reversed)
+
+        val doubleRange = 0.0..9.0
+        val reversedDoubleRange = doubleRange.reversed
+        assertEquals(9.0, reversedDoubleRange.size)
+        assertEquals(9.0, reversedDoubleRange.start)
+        assertEquals(0.0, reversedDoubleRange.end)
+        assertEquals(doubleRange, reversedDoubleRange.reversed)
+
+        assertEquals(IntRange.EMPTY, IntRange.EMPTY.reversed)
+        assertEquals(FloatRange.EMPTY, FloatRange.EMPTY.reversed)
+    }
 }