Typecheck instructions are supported for reified T

compiler/testData/codegen/boxWithStdlib/reified/checkcast.kt

@@ -0,0 +1,20 @@
+import kotlin.test.assertEquals
+
+inline fun<reified T> checkcast(x: Any?): T {
+    return x as T
+}
+
+fun box(): String {
+    val x = checkcast<String>("abc")
+    assertEquals("abc", x)
+    val y = checkcast<Int>(1)
+    assertEquals(1, y)
+
+    try {
+        val z = checkcast<Int>("abc")
+    } catch (e: Exception) {
+        return "OK"
+    }
+
+    return "Fail"
+}