Fix build with -DCLR_CMAKE_USE_SYSTEM_BROTLI=true

[omajid]

Currently, this fails on Fedora 41:

$ ./build.sh  --cmakeargs  -DCLR_CMAKE_USE_SYSTEM_BROTLI=true /p:FullAssemblySigningSupported=false
...
[100%] Linking CXX executable singlefilehost
ld.lld: error: undefined symbol: BrotliDecoderCreateInstance
>>> referenced by entrypoints.c
>>> entrypoints.c.o:(s_compressionNative) in archive ../libs-native/System.IO.Compression.Native/libSystem.IO.Compression.Native.a

This seems to be a regression introduced when this bit was accidentally dropped:
https://github.com/dotnet/runtime/pull/109707/files#diff-7a160e52815fdd808d9415ada41dd5b1748826b27c78277e14f4adcf1ce61511

Fix the build by re-introducing it.

Fixes: #110751

[jkoritzinsky]

Can we move these into Compression.Native/CMakeLists.txt and add the two libraries to the BROTLI_LIBRARIES variable? That would keep all of the brotli handling together.

[omajid]

Does the updated change look okay?

[omajid]

Wait, this doesn't work at all :(

[omajid]

Ah, because src/native/corehost/apphost/static/CMakeLists.txt only includes NATIVE_LIBS

runtime/src/native/corehost/apphost/static/CMakeLists.txt

Lines 183 to 185 in d7e85d9

	# additional requirements for System.IO.Compression.Native
	include(${CLR_SRC_NATIVE_DIR}/libs/System.IO.Compression.Native/extra_libs.cmake)
	append_extra_compression_libs(NATIVE_LIBS)

Should it include BROTLI_LIBRARIES under a CLR_CMAKE_USE_SYSTEM_BROTL conditional?

[jkoritzinsky]

The BROTLI_LIBRARIES values should be propagated up to the static apphost due to

runtime/src/native/libs/System.IO.Compression.Native/CMakeLists.txt

Line 99 in d7e85d9

target_link_libraries(System.IO.Compression.Native-Static PUBLIC ${BROTLI_LIBRARIES})

and

runtime/src/native/libs/System.IO.Compression.Native/CMakeLists.txt

Line 152 in d7e85d9

target_link_libraries(System.IO.Compression.Native-Static PUBLIC ${BROTLI_LIBRARIES})

You can change it back to how it was before to unblock and I can investigate later.