Tensorflowlite flex delegate not loaded automatically when interpreter created even though tensorflowlite_flex.dll provided. (C++ on windows)
Hi @pcoramasionwu, thanks for reporting the issue.

I'm not quite sure what you mean by "if I provide tensorflowlite.dll.if.lib and tensorflowlite_flex.dll.if.lib as Linker dependencies", where are these files coming from? and how did you provide them as Linker dependencies? If you are using command prompt/power shell, please include exact commands. Similarly, what are the exact steps you use to produce the tensorflowlite.dll and tensorflowlite_flex.dll files? Thanks for any additional information you can provide, that will help us resolve your issue faster. Hi @pkgoogle 

**tensorflowlite.dll.if.lib** and **tensorflowlite.dll** are generated by using the following command at the root of the local tensorflow repo on a windows machine:

`bazel build --explain=file_tflite.txt --verbose_explanations --verbose_failures --subcommands //tensorflow/lite:tensorflowlite`

**tensorflowlite_flex.dll.if.lib** and **tensorflowlite_flex.dll** are produced by the follow command: 

`bazel build --explain=file_flex.txt --verbose_explanations --verbose_failures --subcommands tensorflow/lite/delegates/flex:tensorflowlite_flex`

the .libs are added as linker dependencies within visual studio (https://learn.microsoft.com/en-us/cpp/build/reference/dot-lib-files-as-linker-input?view=msvc-170#to-add-lib-files-as-linker-input-in-the-development-environment) Hi @nutsiepully, can you please take a look? Thanks.
### Issue type

Bug

### Have you reproduced the bug with TensorFlow Nightly?

No

### Source

source

### TensorFlow version

tf 2.11

### Custom code

No

### OS platform and distribution

Windows 10

### Mobile device

_No response_

### Python version

_No response_

### Bazel version

5.3

### GCC/compiler version

MSVC 16 (2019)

### CUDA/cuDNN version

_No response_

### GPU model and memory

_No response_

### Current behavior?


When running an application that uses a model that uses select ops, if I provide tensorflowlite.dll.if.lib and tensorflowlite_flex.dll.if.lib as Linker dependencies and place both tensorflowlite.dll and tensorflowlite_flex.dll in the application folder, the flex delegate is not loaded before inference.


When invoke is called on the interpreter we get the error message:
ERROR: Select TensorFlow op(s), included in the given model, is(are) not supported by this interpreter. Make sure you apply/link the Flex delegate before inference.

### Standalone code to reproduce the issue

```shell
The issue is reproducible using the tensorflow test code:
https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/model_flex_test.cc

---------------

The problem is the flex delegate is not automatically applied successfully here https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/core/interpreter_builder.cc#L179

This is because nullptr is being passed to getProcAddress() rather than a handle to tensorflowlite_flex.dll here https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/shared_library.h#L42

---------------

When I modify the tensorflow sources to pass a handle to tensorflowlite_flex.dll, things work as expected
```


### Relevant log output

```shell
ERROR: Select TensorFlow op(s), included in the given model, is(are) not supported by this interpreter. Make sure you apply/link the Flex delegate before inference.
```
