Index: cmake/Modules/AddCompilerRT.cmake
===================================================================
--- cmake/Modules/AddCompilerRT.cmake
+++ cmake/Modules/AddCompilerRT.cmake
@@ -297,6 +297,7 @@
     if(type STREQUAL "SHARED")
       rt_externalize_debuginfo(${libname})
     endif()
+    set_property(GLOBAL APPEND PROPERTY LLVM_RUNTIMES ${libname})
   endforeach()
   if(LIB_PARENT_TARGET)
     add_dependencies(${LIB_PARENT_TARGET} ${libnames})