add missing clang flag

.gitlab-ci.yml

@@ -2111,7 +2111,7 @@ benchmark_ClangBuildAnalyzer:
     - export PATH+=:$(pwd)
     - mkdir $CI_PROJECT_DIR/build
     - cd $CI_PROJECT_DIR/build
-    - cmake .. -DWALBERLA_BUFFER_DEBUG=OFF -DWALBERLA_BUILD_TESTS=OFF -DWALBERLA_BUILD_BENCHMARKS=OFF -DWALBERLA_BUILD_TUTORIALS=OFF -DWALBERLA_BUILD_TOOLS=OFF -DWALBERLA_BUILD_WITH_MPI=ON -DWALBERLA_BUILD_WITH_CUDA=OFF -DWALBERLA_BUILD_WITH_PYTHON=OFF -DWALBERLA_BUILD_WITH_OPENMP=OFF -DCMAKE_BUILD_TYPE=RELEASE -DMPIEXEC_PREFLAGS=$MPIEXEC_PREFLAGS -DWALBERLA_DOUBLE_ACCURACY=ON -DWARNING_ERROR=ON -DWALBERLA_BUILD_WITH_METIS=OFF -DWALBERLA_BUILD_WITH_PARMETIS=OFF -DWALBERLA_OPTIMIZE_FOR_LOCALHOST=ON -DWALBERLA_BUILD_WITH_FASTMATH=ON -DWALBERLA_BUILD_WITH_LTO=ON -G Ninja
+    - cmake .. -DWALBERLA_BUFFER_DEBUG=OFF -DWALBERLA_BUILD_TESTS=OFF -DWALBERLA_BUILD_BENCHMARKS=OFF -DWALBERLA_BUILD_TUTORIALS=OFF -DWALBERLA_BUILD_TOOLS=OFF -DWALBERLA_BUILD_WITH_MPI=ON -DWALBERLA_BUILD_WITH_CUDA=OFF -DWALBERLA_BUILD_WITH_PYTHON=OFF -DWALBERLA_BUILD_WITH_OPENMP=OFF -DCMAKE_BUILD_TYPE=RELEASE -DMPIEXEC_PREFLAGS=$MPIEXEC_PREFLAGS -DWALBERLA_DOUBLE_ACCURACY=ON -DWARNING_ERROR=ON -DWALBERLA_BUILD_WITH_METIS=OFF -DWALBERLA_BUILD_WITH_PARMETIS=OFF -DWALBERLA_OPTIMIZE_FOR_LOCALHOST=ON -DWALBERLA_BUILD_WITH_FASTMATH=ON -DWALBERLA_BUILD_WITH_LTO=ON -DCMAKE_CXX_FLAGS=-ftime-trace -G Ninja
     - cmake . -LAH
     - ClangBuildAnalyzer --start src
     - ninja src/all