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/libvapours/include/vapours/util.hpp

@@ -18,6 +18,7 @@
 #include <vapours/common.hpp>
 #include <vapours/assert.hpp>
 
+#include <vapours/util/util_type_traits.hpp>
 #include <vapours/util/util_alignment.hpp>
 #include <vapours/util/util_size.hpp>
 #include <vapours/util/util_endian.hpp>