Provide an alternative PAL override mechanism

[GregoryComer]

🚀 The feature, motivation and pitch

Empirically, weak symbol overrides can be difficult to use reliably, either relying on specific linkage configurations or non-portable behavior. It can be difficult to get right and is not available on all platforms. We_ need an alternative mechanism to override the PAL.

See #10432 for a wider discussion for the motivation.

Alternatives

No response

Additional context

No response

RFC (Optional)

No response

cc @larryliu0820 @JacobSzwejbka @lucylq

[GregoryComer]

Resolved with #10675