github: Build the split-file executable for the compiler-rt tests too

Since f52f8e817ea36e003e8f09672de48c3c460093f4 (Aug 28th) in
llvm-project, this is needed for one test in compiler-rt.

.github/workflows/build.yml

@@ -487,7 +487,7 @@ jobs:
             -DLLVM_TARGETS_TO_BUILD=X86 `
             -DCMAKE_C_COMPILER=clang `
             -DCMAKE_CXX_COMPILER=clang++
-          ninja not FileCheck llvm-config KillTheDoctor count
+          ninja not FileCheck llvm-config KillTheDoctor count split-file
           echo "LLVM_CONFIG=$PWD\bin\llvm-config.exe" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf8 -Append
           echo "CMAKE_DIR=$PWD\lib\cmake\llvm" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf8 -Append
       - name: Build and test compiler-rt