View CreationMeta are not propagated when chaining views

[albanD]

As per title.
Example failing code that generates potentially wrong gradients:

import torch

a = torch.rand(10, requires_grad=True).clone()

# View for which inplace are invalid
b = a.unbind(0)
# Chain of view where the last one is valid for inplace
c = b[0].view_as(b[0])

# This one should fail but does not
c.mul_(2)
# This one properly fails
b.mul_(2)

In general, the CreationMeta should be inherited from the previous view to ensure invalid chain of views are properly forbidden.

cc @ezyang @albanD @zou3519 @gqchen @pearu @nikitaved @soulitzer

[ezyang]

Doesn't seem too difficult to fix.