message: Add match invoke-virtual flavor
  Summary: As title. To be used in the next diff
diff: @@ -333,6 +333,26 @@ match_t<IRInstruction, std::tuple<match_t<IRInstruction, P> > >
  match_t<IRInstruction, std::tuple<match_t<IRInstruction> > >
  invoke_static();
  +/** invoke-virtual flavors */
  +template <typename P>
  +match_t<IRInstruction, std::tuple<match_t<IRInstruction, P> > >
  + invoke_virtual(const match_t<IRInstruction, P>& p) {
  + return {
  + [](const IRInstruction* insn, const match_t<IRInstruction, P>& p) {
  + auto opcode = insn->opcode();
  + if (opcode == OPCODE_INVOKE_VIRTUAL) {
  + return p.matches(insn);
  + } else {
  + return false;
  + }
  + },
  + p
  + };
  +}
  +
  +match_t<IRInstruction, std::tuple<match_t<IRInstruction> > >
  + invoke_virtual();
  +
  /** invoke of any kind */
  template <typename P>
  match_t<IRInstruction, std::tuple<match_t<IRInstruction, P> > >
  