Add "device not supported" assert to inductor (#112001)

Fixes #111999

Adds an assert that provides a more informative error message

For example, when running a compiled function with mps (currently unsupported):
```
...
  File "/Users/andrew.hu/Desktop/pytorch/torch/_inductor/graph.py", line 927, in init_wrapper_code
    assert wrapper_code_gen_cls is not None, f"Device {device_type} not supported"
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
torch._dynamo.exc.BackendCompilerFailed: backend='inductor' raised:
AssertionError: Device mps not supported
```

Pull Request resolved: #112001
Approved by: https://github.com/peterbell10

torch/_inductor/graph.py

@@ -922,6 +922,7 @@ def init_wrapper_code(self):
         only_cpu = len(device_types) == 0
         device_type = "cpu" if only_cpu else device_types.pop()
         wrapper_code_gen_cls = get_wrapper_codegen_for_device(device_type)
+        assert wrapper_code_gen_cls is not None, f"Device {device_type} not supported"
         self.wrapper_code = wrapper_code_gen_cls()
 
     def codegen(self):