[CMake] Use libcxx-abi-* targets for in-tree sanitizer C++ ABI

When in-tree libcxx is selected as the sanitizer C++ ABI, use
libcxx-abi-* targets rather than libcxxabi and libunwind directly.

Differential Revision: https://reviews.llvm.org/D134855

GitOrigin-RevId: 414f9b7d2f45670019dc8ec284b685a9e238718f
9 files changed