libtorch-bin: cleanup passthru test

- Make passthru.tests an attrset.
- Remove CMake VERBOSE option.
- Remove spurious `cat CMakeLists.txt`.
- Run the test as well.
- Actually test some functionality.

pkgs/development/libraries/science/math/libtorch/test/test.cpp

@@ -1,7 +1,20 @@
-#include <torch/torch.h>
+#undef NDEBUG
+#include <cassert>
+
 #include <iostream>
 
+#include <torch/torch.h>
+
 int main() {
   torch::Tensor tensor = torch::eye(3);
-  std::cout << tensor << std::endl;
+
+  float checkData[] = {
+    1, 0, 0,
+    0, 1, 0,
+    0, 0, 1
+  };
+
+  torch::Tensor check = torch::from_blob(checkData, {3, 3});
+
+  assert(tensor.allclose(check));
 }