Add missing runtime libraries and LLVMgold.so symlink.

We need to ensure that we have the same runtime libraries for sanitizers
in the darwin prebuilts right now (although this can get fixed in the
future). We also need to symlink LLVMgold.so, since we didn't
cherry-pick the fix to use the .dylib equivalent on darwin yet.

Bug: http://b/62580008
Test: https://goto.google.com/clang-4393122-testing
Change-Id: I91ceba711910f5ddaad8d4f83551b3a14438b7bf
162 files changed