Refactor sanitized library on-disk layout - bionic.

This CL changes the linker to point to the newly refactored location
of ASAN-ified libraries on disk.

This supports changes made by the following CLs -
https://android-review.googlesource.com/#/c/359087/
https://android-review.googlesource.com/#/c/359389/

Which refactor the on-disk location as follows:
/data/lib* --> /data/asan/system/lib*
/data/vendor/* --> /data/asan/vendor/*

There are a couple of advantages to this, including better isolation
from other components, and more transparent linker renaming and
SELinux policies.

Bug: 36574794
Bug: 36674745
Test: m -j40 && SANITIZE_TARGET="address" m -j40 and the device
boots. All sanitized libraries are correctly located in /data/asan/*.

Change-Id: Iad8b298a66c38eb0f6327f6b51027f0728aa7a40