add boost::intrusive_ptr to list of smart points in plugins

and fix some loplugin:simplifypointertobool warnings

Change-Id: I3644c390a3339a4cb8d66d6d034a0f043de9320c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/95572
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

compilerplugins/clang/plugin.cxx

@@ -856,7 +856,8 @@ bool isSmartPointerType(const Expr* e)
            || tc2.Class("ScopedReadAccess").Namespace("Bitmap").GlobalNamespace()
            || tc2.Class("ScopedVclPtrInstance").GlobalNamespace()
            || tc2.Class("VclPtr").GlobalNamespace()
-           || tc2.Class("ScopedVclPtr").GlobalNamespace())
+           || tc2.Class("ScopedVclPtr").GlobalNamespace()
+           || tc2.Class("intrusive_ptr").Namespace("boost").GlobalNamespace())
     {
         return true;
     }