llvm-libc: Add Android specific files after initial import

Third-Party Import of: https://github.com/llvm/llvm-project.git
Request Document: go/android3p
For CL Reviewers: go/android3p#cl-review
For Build Team: go/ab-third-party-imports
Test: mm && llvm-nm $(find $OUT -name llvmlibc.a) | grep -q bsearch
Bug: 321313756

Change-Id: Idb132fa258c008fe52965af46e5eed21c51bca54
5 files changed