[IR] Make add/remove Attributes use AttrBuilder instead of AttributeList

This change cleans up call sites and avoids creating temporary
AttributeList objects.

NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301697 91177308-0d34-0410-b5e6-96231b3b80d8
12 files changed