preprocessor/8505: cross cpp0 use PREFIX_INCLUDE_DIR=$prefix/include

[Zack Weinberg]

Daniel Jacobowitz <drow@mvista.com> writes:

>> 
>> I would appreciate opinions.  Dan, I'm cc:ing you because you've had
>> your fingers in this area recently.
>
> If you look at 3.4, you'll see the test has changed:
> if test x$with_sysroot = x && test x$host = x$target \
>    && test "$prefix" != "/usr" && test "x$prefix" != "x$local_prefix" ; then
>   AC_DEFINE_UNQUOTED(PREFIX_INCLUDE_DIR, "$prefix/include")
> fi
>
> i.e. cross compilers no longer search $prefix/include/.  I'm sre it'll
> break someone's setup somewhere; however, it also just makes more sense
> this way.

Ah, ok, I will close the PR then.

zw