* gcc.c (do_spec_1): Implement %j spec flag.
	Remove dead comment.

	* gcc.texi (The Configuration File): Document HOST_BIT_BUCKET.
        * system.h (HOST_BIT_BUCKET): Default to "/dev/null".
        * config/i386/xm-dos.h (HOST_BIT_BUCKET): Define as "NUL".
        * config/i386/xm-os2.h, config/winnt/winnt.h: Likewise.
      * protoize.c (munge_compile_params): Use HOST_BIT_BUCKET (if
	writable) instead of hardcoded value.

	* toplev.c (compile_file): Output to a file even if -fsyntax-only.

        * gcc.c, config/i386/xm-dos.h, config/i386/xm-os2.h: Kill
        MKTEMP_EACH_FILE.

         * gcc.c (cc1_options): Do not process -o or
        run the assembler if -fsyntax-only.

From-SVN: r35849