libstdc++: Minor header cleanup in <numeric>

When adding new features to <numeric> I included the required headers
adjacent to the new code. This cleans it up by moving all the includes
to the start of the file.

libstdc++-v3/ChangeLog:

	* include/std/numeric: Move all #include directives to the top
	of the header.
	* testsuite/26_numerics/gcd/gcd_neg.cc: Adjust dg-error line
	numbers.
	* testsuite/26_numerics/lcm/lcm_neg.cc: Likewise.

3 files changed, 25 insertions, 30 deletions

diff --git a/libstdc++-v3/include/std/numeric b/libstdc++-v3/include/std/numeric
index 2de6aaf..af1e788 100644
--- a/libstdc++-v3/include/std/numeric
+++ b/libstdc++-v3/include/std/numeric
@@ -60,12 +60,24 @@
 #include <bits/c++config.h>
 #include <bits/stl_iterator_base_types.h>
 #include <bits/stl_numeric.h>
-#include <ext/numeric_traits.h>
 
 #ifdef _GLIBCXX_PARALLEL
 # include <parallel/numeric>
 #endif
 
+#if __cplusplus >= 201402L
+# include <type_traits>
+# include <bit>
+#endif
+
+#if __cplusplus >= 201703L
+# include <bits/stl_function.h>
+#endif
+
+#if __cplusplus > 201703L
+# include <limits>
+#endif
+
 /**
  * @defgroup numerics Numerics
  *
@@ -74,14 +86,11 @@
  * arrays, generalized numeric algorithms, and mathematical special functions.
  */
 
-#if __cplusplus >= 201402L
-#include <type_traits>
-#include <bit>
-
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+#if __cplusplus >= 201402L
 namespace __detail
 {
   // std::abs is not constexpr, doesn't support unsigned integers,
@@ -181,18 +190,10 @@ namespace __detail
     }
 
 #endif // C++17
-
-_GLIBCXX_END_NAMESPACE_VERSION
-} // namespace std
-
 #endif // C++14
 
 #if __cplusplus > 201703L
-#include <limits>
 
-namespace std _GLIBCXX_VISIBILITY(default)
-{
-_GLIBCXX_BEGIN_NAMESPACE_VERSION
   // midpoint
 # define __cpp_lib_interpolate 201902L
 
@@ -241,17 +242,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static_assert( sizeof(_Tp) != 0, "type must be complete" );
       return __a  + (__b - __a) / 2;
     }
-_GLIBCXX_END_NAMESPACE_VERSION
-} // namespace std
-
 #endif // C++20
 
-#if __cplusplus > 201402L
-#include <bits/stl_function.h>
-
-namespace std _GLIBCXX_VISIBILITY(default)
-{
-_GLIBCXX_BEGIN_NAMESPACE_VERSION
+#if __cplusplus >= 201703L
 
 #if __cplusplus > 201703L
 #define __cpp_lib_constexpr_numeric 201911L
@@ -720,10 +713,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   // @} group numeric_ops
+#endif // C++17
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 
+#if __cplusplus >= 201703L
 // Parallel STL algorithms
 # if _PSTL_EXECUTION_POLICIES_DEFINED
 // If <execution> has already been included, pull in implementations
diff --git a/libstdc++-v3/testsuite/26_numerics/gcd/gcd_neg.cc b/libstdc++-v3/testsuite/26_numerics/gcd/gcd_neg.cc
index fa559b6..4294a2c 100644
--- a/libstdc++-v3/testsuite/26_numerics/gcd/gcd_neg.cc
+++ b/libstdc++-v3/testsuite/26_numerics/gcd/gcd_neg.cc
@@ -46,9 +46,9 @@ test01()
   std::gcd<const int&, const int&>(0.1, 0.1);   // { dg-error "from here" }
 }
 
-// { dg-error "must be integers" "" { target *-*-* } 160 }
-// { dg-error "must be integers" "" { target *-*-* } 161 }
-// { dg-error "must not be bool" "" { target *-*-* } 162 }
-// { dg-error "must not be bool" "" { target *-*-* } 163 }
+// { dg-error "must be integers" "" { target *-*-* } 169 }
+// { dg-error "must be integers" "" { target *-*-* } 170 }
+// { dg-error "must not be bool" "" { target *-*-* } 171 }
+// { dg-error "must not be bool" "" { target *-*-* } 172 }
 // { dg-prune-output "deleted function" }
 // { dg-prune-output "incomplete type .*make_unsigned" }
diff --git a/libstdc++-v3/testsuite/26_numerics/lcm/lcm_neg.cc b/libstdc++-v3/testsuite/26_numerics/lcm/lcm_neg.cc
index 7e36c26..114995c 100644
--- a/libstdc++-v3/testsuite/26_numerics/lcm/lcm_neg.cc
+++ b/libstdc++-v3/testsuite/26_numerics/lcm/lcm_neg.cc
@@ -46,9 +46,9 @@ test01()
   std::lcm<const int&, const int&>(0.1, 0.1);   // { dg-error "from here" }
 }
 
-// { dg-error "must be integers" "" { target *-*-* } 174 }
-// { dg-error "must be integers" "" { target *-*-* } 175 }
-// { dg-error "must not be bool" "" { target *-*-* } 176 }
-// { dg-error "must not be bool" "" { target *-*-* } 177 }
+// { dg-error "must be integers" "" { target *-*-* } 183 }
+// { dg-error "must be integers" "" { target *-*-* } 184 }
+// { dg-error "must not be bool" "" { target *-*-* } 185 }
+// { dg-error "must not be bool" "" { target *-*-* } 186 }
 // { dg-prune-output "deleted function" }
 // { dg-prune-output "incomplete type .*make_unsigned" }