Built-in classes derive from AotOperator and are registered in
RegistryContext.aot_operator_classes by register_default_aot_operators.
They validate operator contracts, resolve implementations and emit generated
C. Optional init hooks and the context tensor-pointer ABI are described by the
base class and maintained extension example.
Use the generated operator catalog for current registered names, dtype roles
and lowering restrictions. A class appearing in the registry is not a promise
that all shapes, quantization schemes or dtypes use an optimized kernel.
The reference below follows declared public re-exports; private per-operator
helpers remain implementation details.