* gcore.c: Include solib.h.

	* gcore.c: Include solib.h.
	(gcore_create_callback): Call solib_keep_data_in_core when
	considering not saving memory in core file.
	* solib-svr4.c (svr4_keep_data_in_core): New.
	(_initialize_svr4_solib): Initialize
	svr4_so_ops.keep_data_in_core.
	* solib.c (solib_keep_data_in_core): New.
	* solib.h (solib_keep_data_in_core): Declare.
	* solist.h (struct target_so_ops): Add keep_data_in_core.