Added a new test as suggested by @gottesmm.

Author: Mingsheng Hong

test/SIL/Parser/string_literal.sil

@@ -8,6 +8,8 @@ bb0:
   %2 = const_string_literal utf8 "\u{0B}"
 // CHECK: const_string_literal utf16 "\u{0B}"
   %3 = const_string_literal utf16 "\u{0B}"
+// CHECK: string_literal bytes "ABCD"
+  %4 = string_literal bytes "ABCD"
   %6 = tuple ()                                   // user: %7
   return %6 : $()
 }