Move some tests from boxWithStdlib/ to box/

Move those tests which do not require neither stdlib nor reflect

compiler/testData/codegen/box/classes/kt633.kt

@@ -0,0 +1,23 @@
+class mInt(val i : Int) {
+    override fun toString() : String = "mint: $i"
+    operator fun plus(i : Int) = mInt(this.i + i)
+    operator fun inc() = mInt(i + 1)
+}
+
+class MyArray() {
+    val a = Array<mInt>(10, {mInt(0)})
+    operator fun get(i : mInt) : mInt = a[i.i]
+    operator fun set(i : mInt, v : mInt) {
+        a[i.i] = v
+    }
+}
+
+fun box() : String {
+    val a = MyArray()
+    var i = mInt(0)
+    a[i++]
+    a[i++] = mInt(1)
+    for (i in 0..9)
+        a[mInt(i)]
+    return "OK"
+}