Minor header reorganization for unordered containers

	* include/bits/hashtable_policy.h: Include <tuple>.
	* include/std/unordered_map: Only include <bits/stl_pair.h> instead
	of <utility> and <tuple>.
	* include/std/unordered_set: Likewise.

From-SVN: r254223

libstdc++-v3/ChangeLog

+2017-10-30  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/bits/hashtable_policy.h: Include <tuple>.
+	* include/std/unordered_map: Only include <bits/stl_pair.h> instead
+	of <utility> and <tuple>.
+	* include/std/unordered_set: Likewise.
+
 2017-10-30  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	Implement LWG 2485

libstdc++-v3/include/bits/hashtable_policy.h

@@ -31,7 +31,9 @@
 #ifndef _HASHTABLE_POLICY_H
 #define _HASHTABLE_POLICY_H 1
 
-#include <bits/stl_algobase.h> // for std::min.
+#include <tuple>		// for std::tuple, std::forward_as_tuple
+#include <cstdint>		// for std::uint_fast64_t
+#include <bits/stl_algobase.h>	// for std::min.
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {

libstdc++-v3/include/std/unordered_map

@@ -35,13 +35,12 @@
 # include <bits/c++0x_warning.h>
 #else
 
-#include <utility>
 #include <type_traits>
 #include <initializer_list>
-#include <tuple>
 #include <bits/allocator.h>
 #include <ext/alloc_traits.h>
 #include <ext/aligned_buffer.h>
+#include <bits/stl_pair.h>
 #include <bits/stl_function.h> // equal_to, _Identity, _Select1st
 #include <bits/functional_hash.h>
 #include <bits/hashtable.h>

libstdc++-v3/include/std/unordered_set

@@ -35,13 +35,12 @@
 # include <bits/c++0x_warning.h>
 #else
 
-#include <utility>
 #include <type_traits>
 #include <initializer_list>
-#include <tuple>
 #include <bits/allocator.h>
 #include <ext/alloc_traits.h>
 #include <ext/aligned_buffer.h>
+#include <bits/stl_pair.h>
 #include <bits/stl_function.h> // equal_to, _Identity, _Select1st
 #include <bits/functional_hash.h>
 #include <bits/hashtable.h>