Minor. Add more tests

compiler/testData/codegen/box/inlineClasses/useInlineClassesInsideElvisOperatorGeneric.kt

@@ -0,0 +1,22 @@
+// WITH_STDLIB
+// WORKS_WHEN_VALUE_CLASS
+// LANGUAGE: +ValueClasses, +GenericInlineClassParameter
+
+OPTIONAL_JVM_INLINE_ANNOTATION
+value class UInt<T: Int>(private val u: T) {
+    fun asResult() = u
+}
+
+fun <T: Int> test(x1: UInt<T>?, x2: UInt<T>?, y: UInt<T>, z: UInt<T>?): Int {
+    val a = x1 ?: y
+    val b = x1 ?: z!!
+    val c = x1 ?: x2 ?: y
+    return a.asResult() + b.asResult() + c.asResult()
+}
+
+fun box(): String {
+    val u1 = UInt(10)
+    val u2 = UInt(20)
+    val r = test(null, null, u1, u2)
+    return if (r != 40) "fail: $r" else "OK"
+}