Reid Kleckner ee4930b688 Re-land r301697 "[IR] Make add/remove Attributes use AttrBuilder instead of AttributeList"
This time, I fixed, built, and tested clang.

This reverts r301712.

llvm-svn: 301981
2017-05-02 22:07:37 +00:00
..
2017-04-20 14:22:47 +00:00