re PR target/58115 (testcase gcc.target/i386/intrinsics_4.c failure)

re PR target/58115 (testcase gcc.target/i386/intrinsics_4.c failure)

        PR target/58115
        * config/rs6000/rs6000.h (SWITCHABLE_TARGET): Define.
        * config/rs6000/rs6000.c: Include target-globals.h.
        (rs6000_set_current_function): Instead of doing target_reinit
        unconditionally, use save_target_globals_default_opts and
        restore_target_globals.

        * config/rs6000/rs6000-builtin.def (mffs, mtfsf): Add builtins for
        FPSCR.
        * config/rs6000/rs6000.c (rs6000_expand_mtfsf_builtin): New.
        (rs6000_expand_builtin): Handle mffs and mtfsf.
        (rs6000_init_builtins): Define mffs and mtfsf.
        * config/rs6000/rs6000.md (UNSPECV_MFFS, UNSPECV_MTFSF): New.
        (rs6000_mffs): New pattern.
        (rs6000_mtfsf): New pattern.

From-SVN: r206554