re PR middle-end/30191 (GCC error: in eliminate_regs_in_insn, at reload1.c:3126)

        PR middle-end/30191
        Revert:
        * reload1.c (eliminate_regs_in_insn): Merge the plus_src "else" and
        the offset == 0 "then" clauses.
        * config/rs6000/predicates.md (gpc_reg_operand): Check for
        reload_in_progress.

From-SVN: r119844