[llvm] [Offload] Lazily initialize platforms in the Offloading API (PR #227084)

[Alex Duran via llvm-commits]

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adurang wrote:

I find this message a bit cryptic but all the options I can think are kind of long...
```suggestion
                              "liboffload was shut down during process exit. Cannot be initialized before olShutDown");
```

https://github.com/llvm/llvm-project/pull/227084