re PR target/44749 (mep-elf fails to build)

re PR target/44749 (mep-elf fails to build)

PR target/44749
* config/mep/mep-protos.h (mep_save_register_info,
mep_reinit_regs, mep_init_regs): Declare.

* config/mep/mep.c: Move all target definitions to the end of the
file to avoid the need for duplicate declarations.
(mep_save_register_info, mep_reinit_regs, mep_init_regs): New.
(mep_reorg_erepeat): Remove unused variables.
(mep_expand_builtin): Likewise.

* config/mep/mep-pragma.c: Don't include rtl.h.
(INVALID_REGNUM): New.
(mep_pragma_coprocessor_which): Call mep-specific rtl-layer bridge
functions.
(mep_pragma_coprocessor_subclass): Rename "class" to "rclass".
Avoid enum/integer math.

From-SVN: r164268