config.gcc (sparcv9-*-solaris2): Default to 32-bit code.

config.gcc (sparcv9-*-solaris2): Default to 32-bit code.

        * config.gcc (sparcv9-*-solaris2): Default to 32-bit code.
        (sparc*-*-solaris): Clean up header files.
        * configure.in (AS_SPARC64_FLAG): Error out if can't find it
        and plan on generating 64-bit code.
        * toplev.c (decode_g_option): Remove LINKER_DOES_NOT_WORK_WITH_DWARF2.
        * config/sparc/sol2-64.h: Delete and reuse for default 64-bit code.
        * config/sparc/sol2-sld-64.h: Rename ...
        * config/sparc/sol2-bi.h: ... here.  Remove the bits that checked
        for AS_SPARC64_FLAG not defined.
        * config/sparc/sol2-gld-bi.h: New.
        * config/sparc/sol2-sld.h: Remove.
        * config/sparc/sol26-sld.h: New.
        * config/sparc/sol2.h: Tidy comments.
        * doc/install.texi: Document sparc-solaris configury changes.

From-SVN: r52251