Restore i386 binary compatibility in Dwarf EH info.

    Restore i386 binary compatibility in Dwarf EH info.
        * config/i386/i386.h (DWARF_FRAME_REGISTERS): Define as 17, the old
        value of FIRST_PSEUDO_REGISTER.
        * frame.h (DWARF_FRAME_REGISTERS): Default to FIRST_PSEUDO_REGISTER.
        (struct frame_state): Use DWARF_FRAME_REGISTERS.
        * dwarfout.c (output_reg_number): Ditto.
        * dwarf2out.c (reg_number, expand_builtin_init_dwarf_reg_sizes): Ditto.
        (DWARF_FRAME_RETURN_COLUMN): Default to DWARF_FRAME_REGISTERS.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@31127 138bc75d-0d04-0410-961f-82ee72b054a4