eliminate warnings from arlex.c

[Ian Lance Taylor]

"Ben Elliston" <bje@au1.ibm.com> writes:

> The file arlex.c, generated from arlex.l, generates some warnings.
> This patch silences those warnings.  The only part I am uncertain
> about is the use of %option nounput.  This looks to be a flex-specific
> option that may not be supported by other versions of lex(1).  Is this
> true?  Does it really matter?

%option is specific to flex.  I personally don't think the cost of a
few warnings is enough to justify requiring flex here, particularly
since we don't distribute flex with the binutils.  But that is just my
opinion.

Ian