Move IR interpreter's tests from ir/loweredIr directory into box

compiler/testData/codegen/box/involvesIrInterpreter/dumpIrAndCheck/unsignedConst.kt

@@ -0,0 +1,15 @@
+// TARGET_BACKEND: JVM_IR
+// WITH_STDLIB
+
+const val byteVal: UByte = 1u
+const val shortVal: UShort = 2u
+const val intVal: UInt = 3u
+const val longVal: ULong = 4uL
+
+fun box(): String {
+    if (byteVal != 1u.toUByte())    return "Fail 1"
+    if (shortVal != 2u.toUShort())  return "Fail 2"
+    if (intVal != 3u.toUInt())      return "Fail 3"
+    if (longVal != 4u.toULong())    return "Fail 4"
+    return "OK"
+}