Add sbr_lazy_vector and adjust (e)vrp sparse cache

Add sbr_lazy_vector and adjust (e)vrp sparse cache

Add a sparse vector class for cache and use if by default.
Rename the evrp_* params to vrp_*, and add a param for small CFGS which use
just the original basic vector.

	* gimple-range-cache.cc (sbr_vector::sbr_vector): Add parameter
	and local to optionally zero memory.
	(br_vector::grow): Only zero memory if flag is set.
	(class sbr_lazy_vector): New.
	(sbr_lazy_vector::sbr_lazy_vector): New.
	(sbr_lazy_vector::set_bb_range): New.
	(sbr_lazy_vector::get_bb_range): New.
	(sbr_lazy_vector::bb_range_p): New.
	(block_range_cache::set_bb_range): Check flags and Use sbr_lazy_vector.
	* gimple-range-gori.cc (gori_map::calculate_gori): Use
	param_vrp_switch_limit.
	(gori_compute::gori_compute): Use param_vrp_switch_limit.
	* params.opt (vrp_sparse_threshold): Rename from evrp_sparse_threshold.
	(vrp_switch_limit): Rename from evrp_switch_limit.
	(vrp_vector_threshold): New.