abort/error: print backtrace, abuse templates, overhaul result/diag (macos not done yet)

exosphere/warmboot/source/warmboot_main.cpp

@@ -98,7 +98,7 @@ namespace ams::warmboot {
 
 namespace ams::diag {
 
-    void AbortImpl() {
+    NORETURN void AbortImpl() {
         warmboot::ExceptionHandler();
     }