Summary:
This diff adds line-editing to llgoi, by
vendoring and using github.com/peterh/liner.
I have only implemented the basics here;
follow-ups will come later to add persisted
history, and completion,
Reviewers: pcc
Reviewed By: pcc
Subscribers: axw, llvm-commits
Differential Revision: http://reviews.llvm.org/D9811
llvm-svn: 238100
Andrew Wilkins