Roslyn's runtime-async lowering uses AsyncHelpers.Await(Task) for Task awaitables (already handled by TransformAsyncHelpersAwaitToAwait in EarlyExpressionTransforms) but emits a manual GetAwaiter / get_IsCompleted / AsyncHelpers.UnsafeAwaitAwaiter / GetResult sequence for non-Task awaitables — YieldAwaitable, ConfiguredCancelableAsyncEnumerable.Enumerator from await foreach, etc. Add a new RuntimeAsyncManualAwaitTransform invoked from AsyncAwaitDecompiler's runtime-async dispatch that recognizes the three-block shape (head with stloc awaiter + IsCompleted check + branch, pause block calling UnsafeAwaitAwaiter, completed block starting with GetResult), strips the suspend machinery, and replaces the GetResult call with an Await IL instruction. When GetAwaiter takes the address of a temporary set in the same block, also drop the temporary store and use the underlying awaitable expression.
This collapses the LoadsToCatch await-Task.Yield bodies. AsyncForeach should benefit too (its MoveNextAsync awaits go through this path).
Roslyn's runtime-async lowering flattens these into a TryCatch[object] with a captured-rethrow pattern (try-finally) or a TryCatch[T] with a flag-int discriminator and a guarded post-catch body (try-catch). Add a new transform invoked from AsyncAwaitDecompiler when the state-machine matches fail and the method has the runtime-async impl bit; it pattern-matches both shapes and rewrites them back to TryFinally / TryCatch with the original catch body inlined into the handler.
The state-machine and runtime-async lowerings of try-finally use the same catch-handler shape and the same dominator-based finally-body extraction, so promote those to internal static helpers (MatchObjectStoreCatchHandler, MoveDominatedBlocksToContainer) on AwaitInFinallyTransform and call them from the new transform. Filter-bearing catches and multi-handler tries are still left to the standard pipeline.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This way we avoid having to extract later, as we will never inline if the `isinst` argument if this could result in it being unrepresentable in C#.
This commit also refactors inlining restrictions to avoid requiring special cases in ILInlining itself.
But when making this change, I discovered that this broke our pattern-matching tests, and that the weird IL with double `isinst` is indeed generated by the C# compiler for `if (genericParam is StringComparison.Ordinal)` style code. So instead we also allow `isinst` with a `box(expr-without-side-effects)` argument to be represented with the `expr is T ? (T)expr : null` emulation.
Add explicit System.Security.Cryptography.Pkcs dependency to avoid security vulnerability warning in ILSpyCmd.
Suppress security vulnerability warnings in test projects.