Added benchmark for chain of elvises

performance/ring/src/main/kotlin/main.kt

@@ -77,6 +77,7 @@ class RingLauncher : Launcher() {
                     "DefaultArgument.testOneOfEight" to BenchmarkEntryWithInit.create(::DefaultArgumentBenchmark, { testOneOfEight() }),
                     "DefaultArgument.testEightOfEight" to BenchmarkEntryWithInit.create(::DefaultArgumentBenchmark, { testEightOfEight() }),
                     "Elvis.testElvis" to BenchmarkEntryWithInit.create(::ElvisBenchmark, { testElvis() }),
+                    "Elvis.testCompositeElvis" to BenchmarkEntryWithInit.create(::ElvisBenchmark, { testCompositeElvis() }),
                     "Euler.problem1bySequence" to BenchmarkEntryWithInit.create(::EulerBenchmark, { problem1bySequence() }),
                     "Euler.problem1" to BenchmarkEntryWithInit.create(::EulerBenchmark, { problem1() }),
                     "Euler.problem2" to BenchmarkEntryWithInit.create(::EulerBenchmark, { problem2() }),

performance/ring/src/main/kotlin/org/jetbrains/ring/ElvisBenchmark.kt

@@ -37,4 +37,17 @@ open class ElvisBenchmark {
             Blackhole.consume(obj?.value ?: 0)
         }
     }
+
+    class Composite(val x : Int, val y : Composite?)
+
+    fun check(a : Composite?) : Int {
+        return a?.y?.x ?: (a?.x ?: 3)
+    }
+
+    fun testCompositeElvis(): Int {
+        var result = 0
+        for (i in 0..BENCHMARK_SIZE)
+            result += check(Composite(Random.nextInt(), Composite(Random.nextInt(), null)))
+        return result
+    }
 }