[llvm] [DAG] Add SDPatternMatch m_ZExtOrSelf/m_SExtOrSelf/m_AExtOrSelf/m_TruncOrSelf matchers (PR #85480)

[Marc Auberer via llvm-commits]

marcauberer wrote:

@RKSimon can you merge? I do not have commit permissions.

https://github.com/llvm/llvm-project/pull/85480