add cppunit tests to vim-ide-integration

Change-Id: I5a03ff6d6e740d8032030d1590837610f39acd5e
Reviewed-on: https://gerrit.libreoffice.org/31273
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

bin/gbuild-to-ide

@@ -358,7 +358,7 @@ class VimIntegrationGenerator(IdeIntegrationGenerator):
 
     def emit(self):
         global_list = []
-        for lib in set(self.gbuildparser.libs):
+        for lib in set(self.gbuildparser.libs) | set(self.gbuildparser.tests):
             entries = []
             for file in lib.cxxobjects:
                 filePath = os.path.join(self.gbuildparser.srcdir, file) + ".cxx"