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/fsmitm_romstorage.hpp

@@ -42,7 +42,7 @@ class RomFileStorage : public IROStorage {
             if (out_sz != size && out_sz) {
                 R_TRY(this->Read((void *)((uintptr_t)buffer + out_sz), size - out_sz, offset + out_sz));
             }
-            return ResultSuccess;
+            return ResultSuccess();
         };
         Result GetSize(u64 *out_size) override {
             return fsFileGetSize(this->base_file, out_size);