We have 'if' feature for some things in QAPI, including enum values.
But currently it doesn't work for experimental enum values, as in
generated QEnumLookup structure, the description for additional
features (for example - "unstable") is not surrounded by corresponding
"#ifdef"s.

So let's fix it.

We are going to use it in the next commit, to make unstable x-colo
migration capability optional:

  { 'name': 'x-colo', 'features': [ 'unstable' ], 'if': 'CONFIG_COLO' }

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 scripts/qapi/types.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
index c39d054d2c..18f8734047 100644
--- a/scripts/qapi/types.py
+++ b/scripts/qapi/types.py
@@ -61,10 +61,12 @@ def gen_enum_lookup(name: str,
 
         special_features = gen_special_features(memb.features)
         if special_features != '0':
+            feats += memb.ifcond.gen_if()
             feats += mcgen('''
         [%(index)s] = %(special_features)s,
 ''',
                            index=index, special_features=special_features)
+            feats += memb.ifcond.gen_endif()
 
     if feats:
         ret += mcgen('''
-- 
2.34.1