[JVM IR] ForLoopsLowering: Keep IMPLICIT_NOTNULL type-casts in next()

and `componentN()` calls.

There were issues when we have iterables from Java where the element
type has "not null" type information.

compiler/testData/codegen/box/ranges/javaInterop/javaArrayOfMaybeNullable.kt

@@ -0,0 +1,23 @@
+// !LANGUAGE: +StrictJavaNullabilityAssertions
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+
+// FILE: box.kt
+import kotlin.test.*
+
+fun box(): String {
+    val actualValues = mutableListOf<Int>()
+    for (i in J.arrayOfMaybeNullable()) {
+        actualValues += i
+    }
+    assertEquals(listOf(42, null), actualValues)
+    return "OK"
+}
+
+// FILE: J.java
+public class J {
+    public static Integer[] arrayOfMaybeNullable() {
+        return new Integer[] { 42, null };
+    }
+}