ban PyTorchStreamWriter from writing the same file twice (#61805)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61805
Similar in spirit to https://github.com/pytorch/pytorch/pull/61371.
While writing two files with the same name is allowed by the ZIP format,
most tools (including our own) handle this poorly. Previously I banned
this within `PackageExporter`, but that doesn't cover other uses of the
zip format like TorchScript.
Given that there are no valid use cases and debugging issues caused by
multiple file writes is fiendishly difficult, banning this behavior enitrely.
Differential Revision:
D29748968
D29748968
Test Plan: Imported from OSS
Reviewed By: Lilyjjo
Pulled By: suo
fbshipit-source-id: 0afee1506c59c0f283ef41e4be562f9c22f21023
