Minor. Add tests

compiler/testData/codegen/box/inlineClasses/contextsAndAccessors/kt26858Generic.kt

@@ -0,0 +1,26 @@
+// WITH_STDLIB
+// WORKS_WHEN_VALUE_CLASS
+// LANGUAGE: +ValueClasses, +GenericInlineClassParameter
+
+OPTIONAL_JVM_INLINE_ANNOTATION
+value class Direction<T: Int>(private val direction: T) {
+    fun dx() = dx[direction]
+    fun dy() = dy[direction]
+
+    companion object {
+        private val dx = intArrayOf(0, 1, 0, -1)
+        private val dy = intArrayOf(-1, 0, 1, 0)
+    }
+}
+
+fun box(): String {
+    val dirs = arrayOf(Direction(0), Direction(1), Direction(2), Direction(3))
+    val expectedDx = intArrayOf(0, 1, 0, -1)
+    val expectedDy = intArrayOf(-1, 0, 1, 0)
+    for (i in 0 .. 3) {
+        if (dirs[i].dx() != expectedDx[i]) throw AssertionError()
+        if (dirs[i].dy() != expectedDy[i]) throw AssertionError()
+    }
+
+    return "OK"
+}