[K/N] Added a benchmark on string array loop

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

@@ -142,6 +142,7 @@ class RingLauncher : Launcher() {
                     "ForLoops.floatArrayLoop" to BenchmarkEntryWithInit.create(::ForLoopsBenchmark, { floatArrayLoop() }),
                     "ForLoops.charArrayLoop" to BenchmarkEntryWithInit.create(::ForLoopsBenchmark, { charArrayLoop() }),
                     "ForLoops.stringLoop" to BenchmarkEntryWithInit.create(::ForLoopsBenchmark, { stringLoop() }),
+                    "ForLoops.stringArrayLoop" to BenchmarkEntryWithInit.create(::ForLoopsBenchmark, { stringArrayLoop() }),
                     "ForLoops.uIntArrayLoop" to BenchmarkEntryWithInit.create(::ForLoopsBenchmark, { uIntArrayLoop() }),
                     "ForLoops.uShortArrayLoop" to BenchmarkEntryWithInit.create(::ForLoopsBenchmark, { uShortArrayLoop() }),
                     "ForLoops.uLongArrayLoop" to BenchmarkEntryWithInit.create(::ForLoopsBenchmark, { uLongArrayLoop() }),

kotlin-native/performance/ring/src/main/kotlin/org/jetbrains/ring/ForLoopsBenchmark.kt

@@ -16,6 +16,10 @@ class ForLoopsBenchmark {
 
     private val string: String = charArray.joinToString()
 
+    private val stringArray: Array<String> = Array(BENCHMARK_SIZE) {
+        it.toString()
+    }
+
     private val floatArray: FloatArray = FloatArray(BENCHMARK_SIZE) {
         it.toFloat()
     }
@@ -64,6 +68,14 @@ class ForLoopsBenchmark {
         return sum
     }
 
+    fun stringArrayLoop(): Long {
+        var sum = 0L
+        for (e in stringArray) {
+            sum += e.length.toLong()
+        }
+        return sum
+    }
+
     fun floatArrayLoop(): Double {
         var sum = 0.0
         for (e in floatArray) {