Branching from https://android.googlesource.com/platform/build/+/gingerbread
Enable global prelink.
Merge pull request #1 from ting-yuan/prelink

Add apriori for prelinking
Reserve more space to libraries.
Allow libraries involved to be absent from the link map.
Skip libraries that don't fit in prelink.map.
Fix 2 critical typos.
Merge pull request #2 from ting-yuan/prelink

More fault tolerance
Default alloc_ration/alloc_align should be 1/(multiple of page size) respectively.