Remove tensor_data() call in Python Variable() and nn.Parameter() constructors (#22821)
Summary:
As part of the Variable/Tensor merge, `variable.tensor_data()` should be removed in favor of `variable.detach()`. This PR removes `tensor_data()` call sites in Python `Variable()` and `nn.Parameter()` constructor paths.
Note that this PR is BC-breaking in the following way:
- For Python `Variable()` constructor:
Previously, in-place updating a tensor after it's been used to create a Variable does not bump the Variable's version counter, which causes the following problem:
```python
t = torch.ones(2, 3)
v = torch.autograd.Variable(t).requires_grad_()
y = v * v
t.add_(1) # This bumps version counter of `t`
y.sum().backward() # This computes `v`'s gradient incorrectly before this patch, and throws error after this patch
```
After this patch, in-place updating a tensor after it's been used to create a Variable will also bump the Variable's version counter, thus preserving the correctness of the Variable's version counter.
- For Python `nn.Parameter()` constructor:
Previously, in-place updating a tensor after it's been used to create an nn.Parameter does not bump the nn.Parameter's version counter, which causes the following problem:
```python
t = torch.ones(2, 3)
v = torch.nn.Parameter(t)
y = v * v
t.add_(1) # This bumps version counter of `t`
y.sum().backward() # This computes `v`'s gradient incorrectly before this patch, and throws error after this patch
```
After this patch, in-place updating a tensor after it's been used to create an nn.Parameter will also bump the nn.Parameter's version counter, thus preserving the correctness of the nn.Parameter's version counter.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22821
Differential Revision: D16258030
Pulled By: yf225
fbshipit-source-id: 9a6d68cea1864893193dbefbb6ef0c1d5ca12d78
