Results: Implement namespaced, type-safe results.

Because I was working on multiple things at once, this commit also:
- Adds wrappers for/linker flags to wrap CXX exceptions to make them
  abort. This saves ~0x8000 of memory in every system module.
- Broadly replaces lines of the pattern if (cond) { return ResultX; }
  with R_UNLESS(!cond, ResultX());.
- Reworks the R_TRY_CATCH macros (and the result macros in general).

stratosphere/ams_mitm/source/fs_mitm/fs_dir_utils.hpp

@@ -71,7 +71,7 @@ class FsDirUtils {
                 work_path.str[parent_len] = 0;
             }
 
-            return ResultSuccess;
+            return ResultSuccess();
         }
 
     public:
@@ -137,6 +137,6 @@ class FsDirUtils {
                 } R_END_TRY_CATCH;
             }
 
-            return ResultSuccess;
+            return ResultSuccess();
         }
 };