Populate self.export in InstructionTranslatorBase (#88508)
Summary:
This is a followup to https://github.com/pytorch/pytorch/pull/88354/files#diff-622913fdb49db90d6f3a8ab225b4badb7996023e6498e9f7c6d03fe9f32d0986R836
Reference to self.export got added to InstructionTranslatorBase (i.e. STORE_ATTR) but self.export is populated only for InstructionTranslators.
Here's an example failure
```
File "/scratch/williamwen/work/pytorch/torch/_dynamo/symbolic_convert.py", line 322, in step
getattr(self, inst.opname)(inst)
File "/scratch/williamwen/work/pytorch/torch/_dynamo/symbolic_convert.py", line 844, in STORE_ATTR
not self.export
AttributeError: 'InliningInstructionTranslator' object has no attribute 'export'
```
Let's populate with the base class with export flag.
Test Plan:
python test/dynamo/test_export_mutations.py
python test/dynamo/test_export.py
Pull Request resolved: https://github.com/pytorch/pytorch/pull/88508
Approved by: https://github.com/tugsbayasgalan
