[dynamo][compile-time] Caching VTs to reduce compile-time (#121031)
Reduces the `torch.compile(backend="eager")` for this code
~~~
def fn(x):
for _ in range(10000):
# x = torch.sin(x)
x = torch.ops.aten.sin(x)
# x = sin(x)
return x
~~~
From 18 seconds to 12 seconds.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/121031
Approved by: https://github.com/jansel
