[release/9.0-staging] Fix obtaining type handles of IDynamicInterfaceCastableImplementation #109909
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Backport of #109875 to release/9.0-staging
/cc @MichalStrehovsky
Customer Impact
Hit by a 1st party in #109496. Users using CsWinRT might run into an issue where the compiler optimized away a part of a type that is necessary for execution.
Regression
Not a regression, this was broken since 7.0, but nobody was building WinUI apps with native AOT because CsWinRT didn't support it.
Testing
This requires a bit of bad luck to hit. The compiler will only optimize this away if the only thing that references the type in the entire app is a custom attribute. We now have a targeted test for this situation.
Risk
Low risk, this just suppresses an optimization.
IMPORTANT: If this backport is for a servicing release, please verify that:
The PR target branch is
release/X.0-staging
, notrelease/X.0
.If the change touches code that ships in a NuGet package, you have added the necessary package authoring and gotten it explicitly reviewed.