Fix for KT-7288: VerifyError on accessing array element in 'is' block

#KT-7288 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java

@@ -3581,7 +3581,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
             else {
                 elementType = correctElementType(arrayType);
             }
-            StackValue arrayValue = gen(array);
+            StackValue arrayValue = genLazy(array, arrayType);
             StackValue index = genLazy(indices.get(0), Type.INT_TYPE);
 
             return StackValue.arrayElement(elementType, arrayValue, index);

compiler/testData/codegen/box/arrays/arrayInstanceOf.kt

@@ -0,0 +1,26 @@
+//test [], get and iterator calls
+fun test(createIntNotLong: Boolean): String {
+    val a = if (createIntNotLong) IntArray(5) else LongArray(5)
+    if (a is IntArray) {
+        val x = a.iterator()
+        var i = 0
+        while (x.hasNext()) {
+            if (a[i] != x.next()) return "Fail $i"
+            i++
+        }
+        return "O"
+    } else if (a is LongArray) {
+        val x = a.iterator()
+        var i = 0
+        while (x.hasNext()) {
+            if (a.get(i) != x.next()) return "Fail $i"
+            i++
+        }
+        return "K"
+    }
+    return "fail"
+}
+
+fun box(): String {
+    return test(true) + test(false)
+}

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java

@@ -98,6 +98,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/arrays"), Pattern.compile("^(.+)\\.kt$"), true);
         }
 
+        @TestMetadata("arrayInstanceOf.kt")
+        public void testArrayInstanceOf() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/arrays/arrayInstanceOf.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("arrayPlusAssign.kt")
         public void testArrayPlusAssign() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/arrays/arrayPlusAssign.kt");