cgraph.h (asmname_hasher): Inherit from ggc_ptr_hash.

cgraph.h (asmname_hasher): Inherit from ggc_ptr_hash.

gcc/
	* cgraph.h (asmname_hasher): Inherit from ggc_ptr_hash.  Remove
	redundant typedefs and members.
	* coverage.c (counts_entry): Inherit from pointer_hash.  Remove
	redundant typedefs.
	* dwarf2out.c (cu_hash_table_entry_hasher): Likewise.
	* ipa-devirt.c (odr_name_hasher): Likewise.
	(polymorphic_call_target_hasher): Likewise.
	* ira-costs.c (cost_classes_hasher): Likewise.
	* statistics.c (stats_counter_hasher): Likewise.
	* trans-mem.c (log_entry_hasher): Likewise.
	* tree-ssa-dom.c (expr_elt_hasher): Likewise.
	* tree-ssa-sccvn.c (vn_phi_hasher, vn_reference_hasher): Likewise.
	* tree-ssa-tail-merge.c (same_succ_def): Likewise.
	* var-tracking.c (variable_hasher): Likewise.
	* valtrack.h (dead_debug_hash_descr): Inherit from free_ptr_hash.
	Remove redundant typedefs and members.

From-SVN: r224961