swift

10ab242b - [cxx-interop] Do not install binary `.swiftmodule` files for the overlays

[cxx-interop] Do not install binary `.swiftmodule` files for the overlays This fixes a deserialization failure in the compiler that occurred while loading the CxxStdlib overlay module: ``` Cross-reference to module 'Swift' ... Optional ... some ... with type <τ_0_0 where τ_0_0 : ~Copyable, τ_0_0 : ~Escapable> (Optional<τ_0_0>.Type) -> (τ_0_0) -> Optional<τ_0_0> ``` This was happening because the overlays were built against a different version of the Swift stdlib than is being used. The compiler is able to rebuild the Cxx and CxxStdlib modules from their textual interfaces. Let's use that feature unconditionally in production toolchains to avoid this kind of binary incompatibilities. rdar://150416863 (cherry picked from commit 16b280862a80fb5f7977275e21408bd4dd4a872a)