check.h: remove obsolete header

Since we switched from autotools to Meson in commit
94592c1406, we don't need to include
`config.h` early to properly enable large file support.  Meson passes
the required macros on the compiler command line instead of defining
them in `config.h`.

This means we can include `config.h` at any time, whenever we want to
check its macros, and there are no ordering constraints.

src/net/Features.hxx

@@ -20,8 +20,7 @@
 #ifndef NET_FEATURES_HXX
 #define NET_FEATURES_HXX
 
-/* feature macros are defined in config.h, and this header verifies
-   that it has been included earlier */
-#include "check.h"
+/* feature macros are defined in config.h */
+#include "config.h"
 
 #endif

src/net/HostParser.cxx

@@ -30,7 +30,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
 #include "HostParser.hxx"
 #include "util/CharUtil.hxx"
 

src/net/IPv4Address.cxx

@@ -27,7 +27,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
 #include "IPv4Address.hxx"
 
 #include <assert.h>

src/net/IPv6Address.cxx

@@ -27,7 +27,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
 #include "IPv6Address.hxx"
 
 #include <assert.h>

src/net/Init.hxx

@@ -20,7 +20,6 @@
 #ifndef NET_INIT_HXX
 #define NET_INIT_HXX
 
-#include "check.h"
 #include "SocketError.hxx"
 
 #ifdef _WIN32

src/net/Resolver.cxx

@@ -30,7 +30,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
 #include "Resolver.hxx"
 #include "AddressInfo.hxx"
 #include "HostParser.hxx"

src/net/SocketDescriptor.hxx

@@ -30,6 +30,7 @@
 #ifndef SOCKET_DESCRIPTOR_HXX
 #define SOCKET_DESCRIPTOR_HXX
 
+#include "Features.hxx"
 #include "system/FileDescriptor.hxx"
 
 #include <type_traits>

src/net/SocketError.cxx

@@ -17,7 +17,6 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#include "config.h"
 #include "SocketError.hxx"
 #include "util/Macros.hxx"
 

src/net/ToString.hxx

@@ -30,7 +30,6 @@
 #ifndef NET_TO_STRING_HXX
 #define NET_TO_STRING_HXX
 
-#include "check.h"
 #include "util/Compiler.h"
 
 #include <string>