add default definition of EH_RETURN_DATA_REGNO

add default definition of EH_RETURN_DATA_REGNO

gcc/ChangeLog:

2015-04-21  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* defaults.h: New definition of EH_RETURN_DATA_REGNO.
	* except.c: Remove definition of EH_RETURN_DATA_REGNO.
	* builtins.c (expand_builtin): Remove check if
	EH_RETURN_DATA_REGNO is defined.
	* df-scan.c (df_bb_refs_collect): Likewise.
	(df_get_exit_block_use_set): Likewise.
	* haifa-sched.c (initiate_bb_reg_pressure_info): Likewise.
	* ira-lives.c (process_bb_node_lives): Likewise.
	* lra-lives.c (process_bb_lives): Likewise.

From-SVN: r222293