Add CI for Unreal Engine 5.4

[kring]

This builds on #1385 because main is broken.

Closes #1400

[csciguy8]

2. Artifact size for 5.4 seems to be ~2x larger than 5.3. This is a bit concerning.

Good news! I diff'd the artifacts and discovered that the problem seems to be in the Intermediate folder. Usually we see Module.CesiumRuntime.X.cpp.o files in there. But with the new 5.4 build, we're seeing additional .o files (non-unity build).

Bad news, not sure what we did to cause this. From the looks of it, we build 5.4 just like we build 5.3. Worst case we just clean up these extra files before creating the artifact?

[csciguy8]

Also noticed that 5.4 packaging failed...

[11/13] Compile [x64] Module.TestsProject.cpp
[12/13] Link [x64] TestsProject.exe
CesiumGltfReader.lib(GltfReader.obj) : error LNK2005: stbir_resize already defined in Module.ImageCore.cpp.obj
CesiumGltfReader.lib(GltfReader.obj) : error LNK2005: stbir_resize_uint8_srgb already defined in Module.ImageCore.cpp.obj
   Creating library D:\a\cesium-unreal\cesium-unreal\TestsProject\Binaries\Win64\TestsProject.lib and object D:\a\cesium-unreal\cesium-unreal\TestsProject\Binaries\Win64\TestsProject.exp
D:\a\cesium-unreal\cesium-unreal\TestsProject\Binaries\Win64\TestsProject.exe : fatal error LNK1169: one or more multiply defined symbols found

https://github.com/CesiumGS/cesium-unreal/actions/runs/8893486883/job/24432801834

[csciguy8]

[11/13] Compile [x64] Module.TestsProject.cpp [12/13] Link [x64] TestsProject.exe CesiumGltfReader.lib(GltfReader.obj) : error LNK2005: stbir_resize already defined in Module.ImageCore.cpp.obj CesiumGltfReader.lib(GltfReader.obj) : error LNK2005: stbir_resize_uint8_srgb already defined in Module.ImageCore.cpp.obj Creating library D:\a\cesium-unreal\cesium-unreal\TestsProject\Binaries\Win64\TestsProject.lib and object D:\a\cesium-unreal\cesium-unreal\TestsProject\Binaries\Win64\TestsProject.exp D:\a\cesium-unreal\cesium-unreal\TestsProject\Binaries\Win64\TestsProject.exe : fatal error LNK1169: one or more multiply defined symbols found

Module.ImageCore.cpp.obj is an obj file in the 5.4 engine source... which hints that stb symbols were newly defined here in 5.4, and we need to work around this somehow UE_5.4\Engine\Intermediate\Build\Win64\x64\UnrealGame\Development\ImageCore

.

[kring]

Module.ImageCore.cpp.obj is an obj file in the 5.4 engine source... which hints that stb symbols were newly defined here in 5.4, and we need to work around this somehow

Yep. We'll probably have to modify the cesium-native build to optionally not include those sbir functions. We may also have to add ImageCore or similar to CesiumRuntime's .build.cs so that non-packaged builds don't break.

[csciguy8]

I think I have a fix for the packaging test failure (stb linker error). It involved a change to cesium-native so I committed that.

In theory, both cesium-native and cesium-unreal should now be able to build (crossing fingers).

[kring]

If your fix works (it looks promising), then perhaps we can ship UE 5.4 support today after all. I see you cancelled the build, though? Was that because you didn't think it would work, or you were just trying not to use build time during the release?

[csciguy8]

Was that because you didn't think it would work, or you were just trying not to use build time during the release?

It was because I didn't think it would work. I saw an error, then fixed it, then reupdated cesium-native in this PR.

Should be good to go now. Just waiting for CI results for this PR.

We now depend on cesium-native PR #871