Prevent duplicate symbol for dsa_add_new_assertion_failure (#94064)
`dsa_add_new_assertion_failure` is currently causing duplicate definition issues. Possible solutions:
1. Put the device code in a .cu file - requires device linking, which would be very painful to get setup.
2. inline the code - could cause bloat, especially since a function might include many DSAs.
3. Anonymous namespace - balances the above two. Putting the code in a .cu file would ensure that there's a single copy of the function, but it's hard to setup. Inlining the code would cause bloat. An anonymous namespace is easy to setup and produces a single copy of the function per translation unit, which allows the function to be called many times without bloat.
Differential Revision: D42998295
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94064
Approved by: https://github.com/ezyang
