swift

ca14ab71 - [CSSyntaticElement] Desugar types before collecting "in scope" type variables

[CSSyntaticElement] Desugar types before collecting "in scope" type variables Generic type aliases, unless desugared, could bring unrelated type variables into the scope i.e. `TypeAlias<$T, $U>.Context` is actually `_Context<$U>`. These variables could be inferrable only after the the body the closure is solved. To avoid that, let's adjust `TypeVariableRefFinder` to desugar types before collecting referenced type variables. Resolves: rdar://107835060