Use crosscompiler to build LLVM

build-windows.sh

@@ -568,6 +568,10 @@ llvm_build()
     cd ${LLVMDIR}/llvm/build
     cmake -G Ninja \
         -DLLVM_HOST_TRIPLE="x86_64-w64-mingw32" \
+        -DCMAKE_C_COMPILER=x86_64-w64-mingw32-gcc \
+        -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-g++ \
+        -DCMAKE_RC_COMPILER=x86_64-w64-mingw32-windres \
+        -DCMAKE_SYSTEM_NAME=Windows \
         -DCMAKE_BUILD_TYPE="Release" \
         -DCMAKE_INSTALL_PREFIX=${BINDIR} \
         -DLLDB_INCLUDE_TESTS=FALSE \