os: fix os.release() for aix and add test

PR-URL: #10245
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/node_os.cc

@@ -85,7 +85,14 @@ static void GetOSRelease(const FunctionCallbackInfo<Value>& args) {
   if (uname(&info) < 0) {
     return env->ThrowErrnoException(errno, "uname");
   }
+# ifdef _AIX
+  char release[256];
+  snprintf(release, sizeof(release),
+           "%s.%s", info.version, info.release);
+  rval = release;
+# else
   rval = info.release;
+# endif
 #else  // Windows
   char release[256];
   OSVERSIONINFOW info;

test/parallel/test-os.js

@@ -77,6 +77,9 @@ const release = os.release();
 console.log('release = ', release);
 is.string(release);
 assert.ok(release.length > 0);
+//TODO: Check format on more than just AIX
+if (common.isAix)
+  assert.ok(/^\d+\.\d+$/.test(release));
 
 const platform = os.platform();
 console.log('platform = ', platform);