[TableGen] Avoid leaking TreePatternNodes by using shared_ptr.

By using std::shared_ptr for TreePatternNode, we can avoid leaking them.

Reviewers: craig.topper, dsanders, stoklund, tstellar, zturner

Reviewed By: dsanders

Differential Revision: https://reviews.llvm.org/D47463


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333591 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed