SDAG: Update ChainNodesMatched as nodes are deleted

Avoid relying on UB by looking into deleted nodes for a marker value.
Instead, update the list of chain nodes as we go.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271706 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed