swift

f6562d3a - [AutoDiff upstream] differentiable function conversion pipeline (#30660)

[AutoDiff upstream] differentiable function conversion pipeline (#30660) Add the `@differentiable` function conversion pipeline: - New expressions that convert between `@differentiable`, `@differentiable(linear)`, and non-`@differentiable` functions: - `DifferentiableFunction` - `LinearFunction` - `DifferentiableFunctionExtractOriginal` - `LinearFunctionExtractOriginal` - `LinearToDifferentiableFunction` - All the AST handling (e.g. printing) necessary for those expressions. - SILGen for those expressions. - CSApply code that inserts these expressions to implicitly convert between the various function types. - Sema tests for the implicit conversions. - SILGen tests for the SILGen of these expressions. Resolves TF-833.