change some clang plugins to FilteringPlugins

As far as I can tell these do not need to scan everything, so the filtering
(and faster) base plugin is sufficient.

Change-Id: I0912a730bb5ec9670d1faa5c83f573902118cc95
Reviewed-on: https://gerrit.libreoffice.org/68872
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

compilerplugins/clang/dyncastvisibility.cxx

@@ -79,11 +79,11 @@ StringRef vis(Visibility v) {
 }
 
 class DynCastVisibility final:
-    public RecursiveASTVisitor<DynCastVisibility>, public loplugin::Plugin
+    public loplugin::FilteringPlugin<DynCastVisibility>
 {
 public:
     explicit DynCastVisibility(loplugin::InstantiationData const & data):
-        Plugin(data) {}
+        FilteringPlugin(data) {}
 
     bool shouldVisitTemplateInstantiations() const { return true; }
 

compilerplugins/clang/simplifyconstruct.cxx

@@ -18,11 +18,11 @@
 
 namespace
 {
-class SimplifyConstruct : public RecursiveASTVisitor<SimplifyConstruct>, public loplugin::Plugin
+class SimplifyConstruct : public loplugin::FilteringPlugin<SimplifyConstruct>
 {
 public:
     explicit SimplifyConstruct(loplugin::InstantiationData const& data)
-        : Plugin(data)
+        : FilteringPlugin(data)
     {
     }
 

compilerplugins/clang/stringstatic.cxx

@@ -22,13 +22,12 @@
 namespace {
 
 class StringStatic
-    : public clang::RecursiveASTVisitor<StringStatic>
-    , public loplugin::Plugin
+    : public loplugin::FilteringPlugin<StringStatic>
 {
 
 public:
     explicit StringStatic(loplugin::InstantiationData const& rData):
-        Plugin(rData) {}
+        FilteringPlugin(rData) {}
 
     void run() override;
     bool VisitVarDecl(VarDecl const*);

compilerplugins/clang/weakobject.cxx

@@ -19,12 +19,11 @@
 namespace {
 
 class WeakObject
-    : public clang::RecursiveASTVisitor<WeakObject>
-    , public loplugin::Plugin
+    : public loplugin::FilteringPlugin<WeakObject>
 {
 
 public:
-    explicit WeakObject(loplugin::InstantiationData const& rData): Plugin(rData)
+    explicit WeakObject(loplugin::InstantiationData const& rData): FilteringPlugin(rData)
     {}
 
     void run() override {