- when printing a shared node for the second time, don't print its children
(This keeps output proportional to the size of the structure)
- when printing a shared node for the second time, print its type only, not rule
(for consistency with above: don't dump details of nodes twice)
- don't abbreviate shared nodes, to ensure we can prune the tree there
Differential Revision: https://reviews.llvm.org/D128805
Parse forest is the output of the GLR parser, it is a tree-like DAG
which presents all possible parse trees without duplicating subparse structures.
This is a patch split from https://reviews.llvm.org/D121150.
Differential Revision: https://reviews.llvm.org/D122139
Sam McCall