Can't -ast-dump in clang-cl mode

I know -emit-llvm and -ast-dump belong to the frontend actions. The former works as follow
clang-cl /clang:-emit-llvm /clang:-S tmp.cpp
I can get a tmp.ll file as expected, but the following line does not work
clang-cl /clang:-ast-dump /c tmp.cpp
I’ve searched in the clang/lib/Driver/ToolChains/Clang.cpp file , found no occurs of “-ast-dump”. Can I conclude that frontend actions are partially supported in clang-cl mode ? Many thanks!!!