CC=x86_64-w64-mingw32-gcc CXX=x86_64-w64-mingw32-g++ cmake -G "Ninja" -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_INSTALL_PREFIX=/home/william/.local -DLLVM_TARGETS_TO_BUILD="X86" -DCMAKE_SYSTEM_NAME="Windows" ../../llvm/llvm