registers.

The patterns can handle pop multiple with writeback and return (loading into
PC directly).
To handle return, the patterns use a new special predicate
pop_multiple_return, that uses ldm_stm_operation_p function from a previous
patch. To output assembly, the patterns use a new function
arm_output_multireg_pop.

This patch also adds a new function arm_emit_multi_reg_pop
that emits RTL that matches the new pop patterns for integer registers.
This is a helper function for epilogue expansion. It is used by a later
patch.

2012-06-18  Ian Bolton  <ian.bolton@arm.com>
            Sameera Deshpande  <sameera.deshpande@arm.com>
            Greta Yorsh  <greta.yorsh@arm.com>

        * config/arm/arm.md (load_multiple_with_writeback) New define_insn.
        (load_multiple, pop_multiple_with_writeback_and_return) Likewise.
        (pop_multiple_with_return, ldr_with_return) Likewise.
        * config/arm/predicates.md (pop_multiple_return) New special predicate.
        * config/arm/arm-protos.h (arm_output_multireg_pop) New declaration.
        * config/arm/arm.c (arm_output_multireg_pop) New function.
        (arm_emit_multi_reg_pop): New function.


Co-Authored-By: Greta Yorsh <greta.yorsh@arm.com>
Co-Authored-By: Sameera Deshpande <sameera.deshpande@arm.com>

From-SVN: r188739