Allow to search for ignored changes by "is:ignored"

Searching by "is:ignored" is the same as "star:ignore" but is a bit
more intuitive for users.

Change-Id: I63f41662ad1023c98fa746a892d5bfa050303879

Documentation/user-search.txt

@@ -367,6 +367,10 @@ destination branch.
 Mergeability of abandoned changes is not computed. This operator will
 not find any abandoned but mergeable changes.
 
+[[ignored]]
+is:ignored::
++
+True if the change is ignored. Same as `star:ignore`.
 
 [[private]]
 is:private::

gerrit-gwtui/src/main/java/com/google/gerrit/client/SearchSuggestOracle.java

@@ -136,6 +136,7 @@ public class SearchSuggestOracle extends HighlightSuggestOracle {
     suggestions.add("is:merged");
     suggestions.add("is:abandoned");
     suggestions.add("is:mergeable");
+    suggestions.add("is:ignored");
 
     suggestions.add("status:");
     suggestions.add("status:open");

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

@@ -598,6 +598,10 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
       return new SubmittablePredicate(SubmitRecord.Status.OK);
     }
 
+    if ("ignored".equalsIgnoreCase(value)) {
+      return star("ignore");
+    }
+
     try {
       return status(value);
     } catch (IllegalArgumentException e) {