Bogus warning from AIX XL C Compiler/6000?

[Guy Harris]

>	Thus, the escape sequence should not be illegal, and if the
>	warning message is going to print anything it should be
>	the backslash that should be ignored. Has this behavior
>	been outlawed by a recent Standard?

Yes.  *The* recent Standard (ANSI X3.159-1989, "C89") says that "\xNN"
is an escape sequence that means "treat NN as hex digits, and stuff the
character with that value into the string".  See 3.1.3.4 Character
Constants.  (The "NN" is just an example; there's no requirement that
there be exactly two or no more than two characters in the sequence.)