[bc-breaking][quant][graphmode][fx] Add observer/fake_quant for copy nodes (#61687)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61687
Previously we do not insert observer/fake_quant for output copy nodes (e.g. maxpool).
But to produce reference patterns we need to insert observer/fake_quant for the output and later convert that to a quantize
node.
Model:
```
class M(torch.nn.Module):
def __init__(self):
super().__init__()
self.maxpool2d = torch.nn.MaxPool2d(kernel_size=3)
def forward(self, x):
x = self.maxpool2d(x)
return x
```
result of prepare:
Before:
def forward(self, x):
x_activation_post_process_0 = self.x_activation_post_process_0(x); x = None
maxpool2d = self.maxpool2d(x_activation_post_process_0); x_activation_post_process_0 = None
return maxpool2d
After:
def forward(self, x):
x_activation_post_process_0 = self.x_activation_post_process_0(x); x = None
maxpool2d = self.maxpool2d(x_activation_post_process_0); x_activation_post_process_0 = None
maxpool2d_activation_post_process_0 = self.maxpool2d_activation_post_process_0(maxpool2d); maxpool2d = None
return maxpool2d_activation_post_process_0
Test Plan: Imported from OSS
Reviewed By: vkuzo
Differential Revision: D29715566
fbshipit-source-id: 817df9b2933a35cad5331d8d8ce1c5ba0752e9df
