Make Swift SDK host platform independent

[kateinoigakukun]

We currently build Swift SDK for each host platform (macOS x86_64, macOS arm64, Ubuntu, etc...). But in theory, we don't need those variants, we just need a host platform independent single SDK

We need the following changes to make it possible.

• build: Install llvm-ranlib in OSS toolchains swiftlang/swift#72212
• [embedded] Start building and including lld even in Darwin toolchains swiftlang/swift#70715

[kateinoigakukun]

swiftwasm/swiftwasm-build#251 made the SDKs platform independent.
We still need to adjust distribution script to release it as:
swift-wasm-DEVELOPMENT-SNAPSHOT-2024-03-29-a.artifactbundle.zip
instead of
swift-wasm-DEVELOPMENT-SNAPSHOT-2024-03-29-a-ubuntu18.04_x86_64.artifactbundle.zip

[kateinoigakukun]

We now have swift-wasm-DEVELOPMENT-SNAPSHOT-2024-04-14-a-wasm32-unknown-wasi.artifactbundle.zip from yesterday.

See https://github.com/swiftwasm/swift/releases/tag/swift-wasm-DEVELOPMENT-SNAPSHOT-2024-04-14-a