invoke.texi: Document -print-multiarch.

2012-11-14  Matthias Klose  <doko@ubuntu.com>

        * doc/invoke.texi: Document -print-multiarch.
        * doc/install.texi: Document --enable-multiarch.
        * doc/fragments.texi: Document MULTILIB_OSDIRNAMES, MULTIARCH_DIRNAME.
        * configure.ac: Add --enable-multiarch option.
        * configure: Regenerate.
        * Makefile.in (s-mlib): Pass MULTIARCH_DIRNAME to genmultilib.
        enable_multiarch, with_float: New macros.
        if_multiarch: New macro, define in terms of enable_multiarch.
        * genmultilib: Add new argument for the multiarch name.
        * gcc.c (multiarch_dir): Define.
        (for_each_path): Search for multiarch suffixes.
        (driver_handle_option): Handle multiarch option.
        (do_spec_1): Pass -imultiarch if defined.
        (main): Print multiarch.
        (set_multilib_dir): Separate multilib and multiarch names
        from multilib_select.
        (print_multilib_info): Ignore multiarch names in multilib_select.
        * incpath.c (add_standard_paths): Search the multiarch include dirs.
        * cppdefault.h (default_include): Document multiarch in multilib
        member.
        * cppdefault.c: [LOCAL_INCLUDE_DIR, STANDARD_INCLUDE_DIR] Add an
        include directory for multiarch directories.
        * common.opt: New options --print-multiarch and -imultilib.
        * config.gcc <i[34567]86-*-linux* | x86_64-*-linux*> (tmake_file):
        Include i386/t-linux.
        <i[34567]86-*-kfreebsd*-gnu | x86_64-*-kfreebsd*-gnu> (tmake_file):
        Include i386/t-kfreebsd.
        <i[34567]86-*-gnu*> (tmake_file): Include i386/t-gnu.
        * config/i386/t-linux64: Add multiarch names in
        MULTILIB_OSDIRNAMES, define MULTIARCH_DIRNAME.
        * config/i386/t-gnu: New file.
        * config/i386/t-kfreebsd: Likewise.
        * config/i386/t-linux: Likewise.

From-SVN: r193508