PR c++/33255 - Support -Wunused-local-typedefs warning

PR c++/33255 - Support -Wunused-local-typedefs warning

gcc/

	* c-decl.c (lookup_name): Use the new
	maybe_record_typedef_use.
	(pushdecl): Use the new
	record_locally_defined_typedef.
	(store_parm_decls): Allocate cfun->language.
	(finish_function): Use the new maybe_warn_unused_local_typedefs,
	and free cfun->language.
	(c_push_function_context): Allocate cfun->language here only if
	needed.
	(c_pop_function_context): Likewise, mark cfun->language
	for collection only when it should be done.
	* c-common.c (handle_used_attribute): Don't ignore TYPE_DECL
	nodes.
	* c-typeck.c (c_expr_sizeof_type, c_cast_expr): Use the new
	maybe_record_local_typedef_use.

gcc/c-family

	* c-common.h (struct c_language_function::local_typedefs): New
	field.
	(record_locally_defined_typedef, maybe_record_typedef_use)
	(maybe_warn_unused_local_typedefs): Declare new functions.
	* c-common.c (record_locally_defined_typedef)
	(maybe_record_typedef_use)
	(maybe_warn_unused_local_typedefs): Define new functions.
	* c.opt: Declare new -Wunused-local-typedefs flag.

gcc/cp

	* name-lookup.c (pushdecl_maybe_friend_1): Use the new
	record_locally_defined_typedef.
	* decl.c (finish_function): Use the new
	maybe_warn_unused_local_typedefs.
	(grokfield): Use the new record_locally_defined_typedef.
	* parser.c (lookup_name): Use the new maybe_record_typedef_use.

gcc/doc/

	* invoke.texi: Update documentation for -Wunused-local-typedefs.

gcc/testsuite/

	* g++.dg/warn/Wunused-local-typedefs.C: New test file.
	* c-c++-common/Wunused-local-typedefs.c: Likewise.

libstdc++-v3/

	* include/ext/bitmap_allocator.h
	(__detail::__mini_vector::__lower_bound): Remove unused typedef.
	* src/istream.cc (std::operator>>(basic_istream<char>& __in,
	basic_string<char>& __str)): Likewise.
	(std::getline): Likewise.
	* src/valarray.cc (__valarray_product): Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@178692 138bc75d-0d04-0410-961f-82ee72b054a4