Remove AttributeSetNode::get(AttributeList, unsigned) and sink constructor

The getter was equivalent to AttributeList::getAttributes(unsigned),
which seems like a better way to express getting the AttributeSet for a
given index. This static helper was only used in one place anyway.

The constructor doesn't benefit from inlining and doesn't need to be in
a header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299900 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed