upstream

bj/allow-setting-exec_group-in-more-places

swift-exec-group

bj/move-the-c-toolchain-into-its-own-execution-group-so-that-it-does-not-have-to-be-bound-by-the-same-constraints-as-the-execution-platform-selected-for-the-swift-toolchain

bj/fix-swift_toolchain_type-to-work-with-bzlmod-aeg