[llvm] [ADT][APInt] add sfloordiv_ov APInt's member function (PR #84720)

[Jakub Kuderski via llvm-commits]

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@@ -996,6 +996,7 @@ class [[nodiscard]] APInt {
   APInt sshl_ov(unsigned Amt, bool &Overflow) const;
   APInt ushl_ov(const APInt &Amt, bool &Overflow) const;
   APInt ushl_ov(unsigned Amt, bool &Overflow) const;
+  APInt sfloordiv_ov(const APInt &RHS, bool &Overflow) const;
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kuhar wrote:

This deserves some documentation IMO. Could you add a comment explaining what this calculates?

https://github.com/llvm/llvm-project/pull/84720