Generate ubsan shared libraries.

Summary: Those libraries are required by aosp (https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86/+/master/Android.mk). Currenly the shared libraries are generated by aosp Makefile system. We are looking forward to using cmake to generate them.

Reviewers: llvm-commits, vsk

Reviewed By: vsk

Subscribers: filcab, vsk, srhines, kubamracek, mgorny, krytarowski

Differential Revision: https://reviews.llvm.org/D33216

llvm-svn: 303276