Add an integration test for execution.setSubscriptions.

pkg/analysis_server/test/integration/coverage_test.dart

Index: pkg/analysis_server/test/integration/coverage_test.dart
diff --git a/pkg/analysis_server/test/integration/coverage_test.dart b/pkg/analysis_server/test/integration/coverage_test.dart
index 48acfba7cd50ba699cdef406949b5392c997e92c..d5a858831526e3bd1d25070574c62b5b0d304b33 100644
--- a/pkg/analysis_server/test/integration/coverage_test.dart
+++ b/pkg/analysis_server/test/integration/coverage_test.dart
@@ -41,6 +41,12 @@ main() {
           line.substring('##'.length, line.length - 'domain'.length).trim())
       .toSet();
 
+  // Remove any ' (test failed)' suffixes.
+  lines = lines.map((String line) {
+    int index = line.indexOf('(');
+    return index != -1 ? line.substring(0, index).trim() : line;
+  }).toList();
+
   // - [ ] server.getVersion
   Set<String> allMembers = lines
       .where((line) => line.startsWith('- '))