* doc/tm.texi (DWARF_FRAME_REGISTERS): Add documentation.
        (PRE_GCC3_DWARF_FRAME_REGISTERS): Same.

        * unwind-dw2.c (__frame_state_for): Change DWARF_FRAME_REGISTERS
        to PRE_GCC3_DWARF_FRAME_REGISTERS.
        (frame_state): Same.
        (PRE_GCC3_DWARF_FRAME_REGISTERS): Define if not already defined.

Co-Authored-By: Richard Henderson <rth@redhat.com>

From-SVN: r47730