parscan.hpp: put in code for scan

tests/sampler/parscan.hpp

@@ -1 +1,21 @@
+#pragma once
 
+struct Tester {
+  template <typename execution_space>
+  explicit Tester(const execution_space& space) {
+    //! Explicitly launch a kernel with a name, and run it 15 times with kernel
+    //! logger. Use a periodic sampling with skip rate 5. This should print
+    //! out 2 invocations, and there is a single matcher with a regular
+    //! expression to check this.
+
+    long int N = 1024;
+    long int result;
+
+    for (int iter = 0; iter < 15; iter++) {
+      result = 0;
+      Kokkos::parallel_scan("named kernel scan", N, *this, result);
+    }
+  }
+
+  KOKKOS_FUNCTION void operator()(const int, long int&, bool) const {}
+};