io_uring: Add basic wrapper

This is a simple RAII wrapper around a ring instance that structure SQE
/ CQE callbacks to make it convenient for C++ usage.

Change-Id: I9db8b48a81bec8d8aff4a362920f4dd688c27d57
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/meson.build b/test/meson.build
index 8a2ae6c..b303032 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -44,6 +44,16 @@
   warning('Not testing file descriptor feature')
 endif
 
+if has_io_uring
+  gtests += [
+    'io_uring',
+  ]
+elif build_tests.enabled()
+  error('Not testing io_uring feature')
+else
+  warning('Not testing io_uring feature')
+endif
+
 if gtest.found() and gmock.found()
   foreach t : gtests
     test(t, executable(t.underscorify(), t + '.cpp',