message: fix(ci) Remove `github.workspace` on Windows as it contains `\`.
  `github.workspace` uses `\` for the path separator. It creates
  confusion in Bash. This patch just uses the `.llvm` directory to
  contain LLVM, and use `pwd` to get an absolute path for
  `LLVM_SYS_110_PREFIX` and `PATH`.
diff: @@ -100,12 +100,13 @@ jobs:
  shell: bash
  run: |
  curl --proto '=https' --tlsv1.2 -sSf ${{ matrix.llvm_url }} -L -o llvm.tar.gz
  - mkdir ${{ env.LLVM_DIR }}
  - tar xf llvm.tar.gz --strip-components=1 -C ${{ env.LLVM_DIR }}
  - echo "${{ env.LLVM_DIR }}/bin" >> $GITHUB_PATH
  - echo "LLVM_SYS_110_PREFIX=${{ env.LLVM_DIR }}" >> $GITHUB_ENV
  + LLVM_DIR=$(pwd)/${{ env.LLVM_DIR }}
  + mkdir ${LLVM_DIR}
  + tar xf llvm.tar.gz --strip-components=1 -C ${LLVM_DIR}
  + echo "${LLVM_DIR}/bin" >> $GITHUB_PATH
  + echo "LLVM_SYS_110_PREFIX=${LLVM_DIR}" >> $GITHUB_ENV
  env:
  - LLVM_DIR: ${{ github.workspace }}/llvm-11
  + LLVM_DIR: .llvm
  - name: Set up dependencies for Mac OS
  run: |
  brew install automake
  