Some ZIPT test cases

src/test/CMakeLists.txt

@@ -134,6 +134,7 @@ add_executable(test-z3
   seq_nielsen.cpp
   nseq_basic.cpp
   nseq_regex.cpp
+  nseq_zipt.cpp
   small_object_allocator.cpp
   smt2print_parse.cpp
   smt_context.cpp

src/test/main.cpp

@@ -289,6 +289,7 @@ int main(int argc, char ** argv) {
     TST(seq_nielsen);
     TST(nseq_basic);
     TST(nseq_regex);
+    TST(nseq_zipt);
     TST(ho_matcher);
     TST(finite_set);
     TST(finite_set_rewriter);