Switch atmosphere's build target to C++20. (#952)

* ams: update to build with gcc10/c++20

* remove mno-outline-atomics

* ams: take care of most TODO C++20s

* fusee/sept: update for gcc10

* whoosh, your code now uses pre-compiled headers

* make: dependency fixes

libraries/libstratosphere/include/stratosphere/fssrv/fssrv_sf_path.hpp

@@ -43,7 +43,7 @@ namespace ams::fssrv::sf {
         }
     };
 
-    static_assert(std::is_pod<Path>::value && sizeof(Path) == FS_MAX_PATH);
+    static_assert(util::is_pod<Path>::value && sizeof(Path) == FS_MAX_PATH);
 
     using FspPath = Path;