[K/N][tests] Added a bunch of tests on incremental compilation

native/native.tests/testData/caches/ic/changeFileIndex/lib/lib.file1.kt

@@ -0,0 +1,5 @@
+inline fun foo(arr: IntArray, transform: (Int) -> Int): Int {
+    var sum = 0
+    for (x in arr) sum += transform(x)
+    return sum
+}

native/native.tests/testData/caches/ic/changeFileIndex/lib/lib.file2.kt

@@ -0,0 +1,8 @@
+inline fun bar(arr: IntArray, transform: (Int) -> Int): Int {
+    var max = Int.MIN_VALUE
+    for (x in arr) {
+        val y = transform(x)
+        if (y > max) max = y
+    }
+    return max
+}

native/native.tests/testData/caches/ic/changeFileIndex/main/main.kt

@@ -0,0 +1,11 @@
+import kotlin.test.*
+
+@Test
+fun checkFoo() {
+    assertEquals(42, foo(intArrayOf(1, 2, 3, 4, 5, 6)) { it * 2 })
+}
+
+@Test
+fun checkBar() {
+    assertEquals(42, bar(intArrayOf(1, 3, 7)) { it * 6 })
+}