functexcept.h (__throw_out_of_range_fmt): Change attribute to __gnu_printf__ archetype to prevent warnings for "%zu".

	* include/bits/functexcept.h (__throw_out_of_range_fmt): Change
	attribute to __gnu_printf__ archetype to prevent warnings for "%zu".
	* include/bits/locale_facets_nonio.tcc (time_get::do_get_weekday):
	Remove unused typedef.
	(time_get::do_get_monthname): Likewise.
	* include/bits/stl_tree.h: Add system_header pragma.
	* include/ext/stdio_sync_filebuf.h (stdio_sync_filebuf::file): Remove
	redundant const-qualifier.
	* include/std/complex (complex::__rep): Use _GLIBCXX_CONSTEXPR macro
	instead of _GLIBCXX_USE_CONSTEXPR.

From-SVN: r211951