fails:#String#bytesize returns the length of self in bytes
fails:#String#bytesize works with strings containing single UTF-8 characters
fails:#String#bytesize works with pseudo-ASCII strings containing single UTF-8 characters
fails:#String#bytesize works with strings containing UTF-8 characters
fails:#String#bytesize works with pseudo-ASCII strings containing UTF-8 characters
fails:#String#bytesize returns 0 for the empty string
