Add brotli support to FoundationNetworking

[zhenchaoli]

Add brotli as a dependency to enable brotli decoding for curl.

On Windows, only brotlicommon.lib and brotlidec.lib is linked.
brotlienc.lib is intentionally left out as curl does not need it. brotlienc.lib is also much larger in size (~3.8MB).

[zhenchaoli]

swiftlang/swift#83441
@swift-ci please test

[zhenchaoli]

Seems build failed. I see that brotli is not checked out. Do I need a 'clean' test?

According to https://github.com/swiftlang/swift/blob/main/docs/ContinuousIntegration.md, this is a thing, but unsure from reading it whether that will make a difference.

[zhenchaoli]

swiftlang/swift#83441
@swift-ci please clean test

[zhenchaoli]

the related pull request is at swiftlang/swift#83441

[compnerd]

Windows builds the toolchain without SPM and without the dependency automation in WindowsSwiftPMDependencies.cmake. We need this to be wired up into the CMake build properly.

[jmschonfeld]

Windows builds the toolchain without SPM and without the dependency automation in WindowsSwiftPMDependencies.cmake. We need this to be wired up into the CMake build properly.

What extra pieces would need to be wired up in this build here? I know it's expected that the Windows toolchain build wouldn't use WindowsSwiftPMDependencies, but I think that's fine? I don't see any references to zlib in this project and I believe the brotli setup is largely the same, are the build.ps1 updates to pass the appropriate paths in as cmake variables insufficient for CMake to find the project in the dependency graph automatically?

[zhenchaoli]

Windows builds the toolchain without SPM and without the dependency automation in WindowsSwiftPMDependencies.cmake. We need this to be wired up into the CMake build properly.

My reading (and discussion with Jeremy) is that cmake/modules/WindowsSwiftPMDependencies.cmake is for local developments, and that the actual cmake changes are made in swiftlang/swift#83441

The meaty piece in this PR is just the 2 test cases in my opinion.

[compnerd]

Ah, so Foundation itself won't need to link to brotli because curl will automatically ensure that the paths are exported and passed along to the linker?