We can cut a lot of stuff out of the NDK's libandroid_support with this,
and reduce unnecessary relocations for all LP32 code. LP64 code should
be unaffected.
Bug: https://issuetracker.google.com/64450768
Bug: https://github.com/android-ndk/ndk/issues/507
Test: ran tests, plus manual readelf on the _test.o files
Change-Id: I3de6015921195304ea9c829ef31665cd34664066
Future API levels aren't known (e.g. 25 could be a maintenance release
of N that doesn't contain any bionic updates), so use a placeholder
macro that we can find and replace with the actual API level before each
release.
Bug: http://b/28178111
Change-Id: I667fe53ea1ac49b64135170fc30d5dbe9df94e29
