Nonrecursive build within gcc directory

[Richard Kenner]

    There should not be a problem, as long as you're using the "new style"
    Makefile.in - i.e. there's an outputs= line in config-lang.in.

Yup, there is.

If this change goes in, I *do* want to convert Ada's Makefile, but only
once there's no need to further maintain the version for GCC 2.8.

Good.  Thanks.