Fuzzer supported arch - S390xX

Hi there,

Are there any plans of including S390X in ALL_FUZZER_SUPPORTED_ARCH?

https://github.com/llvm-mirror/compiler-rt/blob/master/cmake/config-ix.cmake#L228

It appears that Fuzzer lib is built successfully on s390x if I add S390X to the mix.

Thanks in advance for your help.