[GlobalISel] Move GISelAccessor class into public headers

Reviewers: qcolombet

Subscribers: joker.eph, vkalintiris, llvm-commits

Differential Revision: http://reviews.llvm.org/D19120

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266348 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed