[llvm] [DAG] Add funnel-shift matchers to SDPatternMatch (Fixes #185880) (PR #186593)

[Min-Yih Hsu via llvm-commits]

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mshockwave wrote:

Re: `m_AllOf(m_Value(ShlAmt), m_ConstInt(ShlConst))`

I added a conditional binding variant of `m_Value` recently in #182091 . So you can write it as `m_Value(ShlAmt, m_ConstInt(ShlConst))` instead. Ditto for the case regarding `SrlAmt`

https://github.com/llvm/llvm-project/pull/186593