[1/n] Migrate permute_cols to libtorch stable ABI (#31509)

Signed-off-by: Mikayla Gawarecki <mikaylagawarecki@gmail.com>

csrc/libtorch_stable/torch_bindings.cpp

@@ -0,0 +1,21 @@
+#include "ops.h"
+#include "core/registration.h"
+
+#include <torch/csrc/stable/library.h>
+
+// Register ops with STABLE_TORCH_LIBRARY for libtorch stable ABI compatibility.
+// Note: We register under namespace "_C" so ops are accessible as
+// torch.ops._C.<op_name> for compatibility with existing code.
+STABLE_TORCH_LIBRARY_FRAGMENT(_C, m) {
+#ifndef USE_ROCM
+  m.def("permute_cols(Tensor A, Tensor perm) -> Tensor");
+#endif
+}
+
+STABLE_TORCH_LIBRARY_IMPL(_C, CUDA, m) {
+#ifndef USE_ROCM
+  m.impl("permute_cols", TORCH_BOX(&permute_cols));
+#endif
+}
+
+REGISTER_EXTENSION(_C_stable_libtorch)