[eval.py] add simple architecture variants

eval.py

@@ -207,6 +207,12 @@ EMPER_FLAVORS = {
         'meson_options': '-Dio_cq_lock_implementation=mutex',
         'server_cmd_suffix': '100'
     },
+    'simple-arch': {
+        'meson_options': '-Dio_single_uring=true',
+    },
+    'simple-arch-try-syscall': {
+        'meson_options': '-Dio_single_uring=true -Dio_try_syscall=true',
+    },
     'first': {
         'checkout': EMPER_FIRST_CHECKOUT,
         'patches': ['fix_free_vs_delete.patch', 'wakeup-condvar.patch'],