Add more tests for for-in-array

#KT-21354 Fixed Target versions 1.2.20
 #KT-21321 Fixed Target versions 1.2.20

compiler/testData/codegen/box/controlStructures/forInArray/forInArrayWithArrayPropertyUpdatedInLoopBody.kt

@@ -0,0 +1,12 @@
+// WITH_RUNTIME
+
+var xs = intArrayOf(1, 2, 3)
+
+fun box(): String {
+    var sum = 0
+    for (x in xs) {
+        sum = sum * 10 + x
+        xs = IntArray(0)
+    }
+    return if (sum == 123) "OK" else "Fail: $sum"
+}

compiler/testData/codegen/box/controlStructures/forInArray/forInArrayWithArrayVarUpdatedInLoopBody12.kt

@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+// LANGUAGE_VERSION: 1.2
+// IGNORE_BACKEND: JS
+
+fun box(): String {
+    var xs = intArrayOf(1, 2, 3)
+    var sum = 0
+    for (x in xs) {
+        sum = sum * 10 + x
+        xs = intArrayOf(4, 5)
+    }
+    return if (sum == 15) "OK" else "Fail: $sum"
+}

compiler/testData/codegen/box/controlStructures/forInArray/forInArrayWithArrayVarUpdatedInLoopBody13.kt

@@ -0,0 +1,23 @@
+// WITH_RUNTIME
+// LANGUAGE_VERSION: 1.3
+
+// In Kotlin 1.0, in a for-in-array loop, range expression is cached in
+// a local variable unless it is already a local variable.
+// This caused the following quirky behavior:
+// if an array variable is updated in the loop body, it affects the loop
+// execution (see https://youtrack.jetbrains.com/issue/KT-21354).
+// Most likely it is a bug, however, fixing it right now is a breaking
+// change requiring a proper deprecation loop.
+// When the design decision is made, it might be required to update this
+// test (e.g., by adding a proper LANGUAGE_VERSION directive).
+// Note that JS back-end handles this case "correctly".
+
+fun box(): String {
+    var xs = intArrayOf(1, 2, 3)
+    var sum = 0
+    for (x in xs) {
+        sum = sum * 10 + x
+        xs = intArrayOf(4, 5)
+    }
+    return if (sum == 123) "OK" else "Fail: $sum"
+}

compiler/testData/codegen/box/controlStructures/forInArray/forInDelegatedPropertyUpdatedInLoopBody.kt

@@ -0,0 +1,17 @@
+class Del<T>(var x: T) {
+    operator fun getValue(thisRef: Any?, kProp: Any) = x
+
+    operator fun setValue(thisRef: Any?, kProp: Any, value: T) {
+        x = value
+    }
+}
+
+fun box(): String {
+    var xs by Del(intArrayOf(1, 2, 3))
+    var sum = 0
+    for (x in xs) {
+        sum = sum * 10 + x
+        xs = intArrayOf(4, 5, 6)
+    }
+    return if (sum == 123) "OK" else "Fail: $sum"
+}

compiler/testData/codegen/box/controlStructures/forInArray/forInFieldUpdatedInLoopBody.kt

@@ -0,0 +1,16 @@
+var xs: IntArray = intArrayOf(1, 2, 3)
+    get() = field
+    set(ys) {
+        var sum = 0
+        for (x in field) {
+            sum = sum * 10 + x
+            field = intArrayOf(4, 5, 6)
+        }
+        if (sum != 123) throw AssertionError("sum=$sum")
+        field = ys
+    }
+
+fun box(): String {
+    xs = intArrayOf()
+    return "OK"
+}

compiler/testData/codegen/box/controlStructures/forInArray/forIntArray.kt

@@ -0,0 +1,14 @@
+fun box() : String {
+    val a = arrayOfNulls<Int>(5)
+    var i = 0
+    var sum = 0
+    for(el in 0..4) {
+       a[i] = i++
+    }
+    for (el in (a as Array<Int>)) {
+        sum = sum + el
+    }
+    if(sum != 10) return "a failed"
+
+    return "OK"
+}

compiler/testData/codegen/box/controlStructures/forInArray/forNullableIntArray.kt

@@ -0,0 +1,15 @@
+fun box() : String {
+    val b : Array<Int?> = arrayOfNulls<Int> (5)
+    var i = 0
+    var sum = 0
+    while(i < 5) {
+       b[i] = i++
+    }
+    sum = 0
+    for (el in b) {
+        sum = sum + (el ?: 0)
+    }
+    if(sum != 10) return "b failed"
+
+    return "OK"
+}

compiler/testData/codegen/box/controlStructures/forInArray/forPrimitiveIntArray.kt

@@ -0,0 +1,14 @@
+fun box() : String {
+    val a = IntArray (5)
+    var i = 0
+    var sum = 0
+    for(el in 0..4) {
+       a[i] = i++
+    }
+    for (el in a) {
+        sum = sum + el
+    }
+    if(sum != 10) return "a failed"
+
+    return "OK"
+}