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/pm/pm_types.hpp

@@ -97,6 +97,6 @@ namespace ams::pm {
         u32 event;
         os::ProcessId process_id;
     };
-    static_assert(sizeof(ProcessEventInfo) == 0x10 && std::is_pod<ProcessEventInfo>::value, "ProcessEventInfo definition!");
+    static_assert(sizeof(ProcessEventInfo) == 0x10 && util::is_pod<ProcessEventInfo>::value, "ProcessEventInfo definition!");
 
 }