re PR middle-end/27793 (num_ssa_names inconsistent or immediate use iterator wrong)

re PR middle-end/27793 (num_ssa_names inconsistent or immediate use iterator wrong)

	PR middle-end/27793
	* cp-tree.h (cxx_int_tree_map): New struct.
	(struct language_function): Add extern_decl_map field.
	* name-lookup.c (pushdecl_maybe_friend): Add x -> t mapping
	to cp_function_chain->extern_decl_map hash table instead of
	copying over DECL_UID.
	* cp-gimplify.c (cxx_int_tree_map_eq, cxx_int_tree_map_hash): New
	functions.
	(cp_genericize_r): Remap DECL_EXTERN local decls using
	cp_function_chain->extern_decl_map hash table.
	* decl.c (finish_function): Clear extern_decl_map.

	PR c++/26757
	PR c++/27894
	* g++.dg/tree-ssa/pr26757.C: New test.
	* g++.dg/tree-ssa/pr27894.C: New test.

From-SVN: r114607