PATCH to -MD specs

[David Edelsohn]

Neil, Mark:

	Can this patch be applied to the GCC 3.2 branch as well?  It is a
regression from gcc-2.95.

        PR preprocessor/7862
        PR preprocessor/8190
        * gcc.c (cpp_unique_options): Don't delete .d files.
        Remove stray whitespace.

Thanks, David