Custom ops API small fixes (#2936)

Summary:

Fix the way we use `at::from_blob()` and add proper namespace to `CompileTimeFunctionPointer` so to not confused with `at::CompileTimeFunctionPointer`.

Differential Revision: D55907751

Author: larryliu0820

extension/aten_util/make_aten_functor_from_et_functor.h

@@ -149,8 +149,7 @@ struct type_convert<
     }
     c10::ScalarType scalar_type =
         static_cast<c10::ScalarType>(val.scalar_type());
-    converted =
-        at::from_blob(val.mutable_data_ptr(), val.numel(), sizes, scalar_type);
+    converted = at::from_blob(val.mutable_data_ptr(), sizes, scalar_type);
   }
   ATensor call() {
     return converted;

extension/aten_util/targets.bzl

@@ -27,6 +27,7 @@ def define_common_targets():
         ],
         exported_deps = [
             "//executorch/extension/kernel_util:kernel_util",
+            "//executorch/extension/runner_util:managed_tensor",
             "//executorch/runtime/core:core",
             "//executorch/runtime/core:evalue",
             "//executorch/runtime/core/exec_aten:lib",

extension/kernel_util/meta_programming.h

@@ -49,7 +49,7 @@ struct is_compile_time_function_pointer<
     CompileTimeFunctionPointer<FuncType, func_ptr>> : std::true_type {};
 
 #define EXECUTORCH_FN_TYPE(func)                                      \
-  CompileTimeFunctionPointer<                                         \
+  ::torch::executor::CompileTimeFunctionPointer<                      \
       std::remove_pointer_t<std::remove_reference_t<decltype(func)>>, \
       func>
 #define EXECUTORCH_FN(func) EXECUTORCH_FN_TYPE(func)()