[llvm] [ADT] Add APIntOps::abds signed absolute difference and rename absdiff -> abdu (PR #84791)

[Jay Foad via llvm-commits]

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@@ -362,7 +362,7 @@ TEST(KnownBitsTest, BinaryExhaustive) {
         return KnownBits::absdiff(Known1, Known2);
       },
       [](const APInt &N1, const APInt &N2) {
-        return APIntOps::absdiff(N1, N2);
+        return APIntOps::abdu(N1, N2);
       },
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jayfoad wrote:

Keeping the lambda seems silly if we don't need it, but we can always clean them all up later.

https://github.com/llvm/llvm-project/pull/84791