Revert "build: add AST support"

This reverts commit 97e7cae0a2ea34726ba063689b3ebad9453041c4.

Change-Id: Idceb5ecc4655a8dc004a0050afb7c0d23bcc062f
Merge "Revert "build: add AST support"" into cm-11.0
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_build into cd-4.4