Back out Profile library and dependent commits

Chandler voiced some concern with checking this in without some
discussion first. Reverting for now.

This reverts r203703, r203704, r203708, and 203709.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203723 91177308-0d34-0410-b5e6-96231b3b80d8