Use a different linker for ASan binaries.

Another change in bionic/linker adds linker_asan/linker_asan64 that
know where to find ASan shared libraries.
Also, include linker_asan to the required packages list when building
for ASan.

Change-Id: I8ebe7c0091bbeb0c135708a891d33d9844373d37
5 files changed