Index: llvm/cmake/modules/CrossCompile.cmake
===================================================================
--- llvm/cmake/modules/CrossCompile.cmake
+++ llvm/cmake/modules/CrossCompile.cmake
@@ -57,6 +57,8 @@
          "${LLVM_ENABLE_PROJECTS}")
   string(REPLACE ";" "$<SEMICOLON>" llvm_external_projects_arg
          "${LLVM_EXTERNAL_PROJECTS}")
+  string(REPLACE ";" "$<SEMICOLON>" llvm_enable_runtimes_arg
+         "${LLVM_ENABLE_RUNTIMES}")
 
   set(external_project_source_dirs)
   foreach(project ${LLVM_EXTERNAL_PROJECTS})
@@ -77,6 +79,7 @@
         -DLLVM_TARGET_ARCH="${LLVM_TARGET_ARCH}"
         -DLLVM_ENABLE_PROJECTS="${llvm_enable_projects_arg}"
         -DLLVM_EXTERNAL_PROJECTS="${llvm_external_projects_arg}"
+        -DLLVM_ENABLE_RUNTIMES="${llvm_enable_runtimes_arg}"
         ${external_project_source_dirs}
         -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN="${LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN}"
         ${build_type_flags} ${linker_flag} ${external_clang_dir}