swift

43bb5e41 - swift_build_sdk_interfaces.py: builds compiled modules from an SDK (#25432)

swift_build_sdk_interfaces.py: builds compiled modules from an SDK (#25432) ...by crawling it and looking for module interfaces. This is the tool Apple is using for the "prebuilt-modules" directory in the toolchain in Xcode.app, which avoids even a first-use cost for importing modules from Apple SDKs as long as the SDKs haven't changed. We've been landing changes to support this model on the compiler side, so the tool to generate the "prebuilt" compiled modules belongs in the compiler repo too. (In theory this could be used with open-source toolchains as well, or for alternate SDKs.)