[llvm] [KnownBitsTest] Common up isCorrect and isOptimal. NFC. (PR #89585)

[Jay Foad via llvm-commits]

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@@ -201,23 +186,23 @@ static void TestAddSubExhaustive(bool IsAdd) {
 
       KnownBits KnownComputed = KnownBits::computeForAddSub(
           IsAdd, /*NSW=*/false, /*NUW=*/false, Known1, Known2);
-      EXPECT_TRUE(isOptimal(Known, KnownComputed, {Known1, Known2}));
+      EXPECT_TRUE(checkResult(Known, KnownComputed, {Known1, Known2},
+                              /*CheckOptimality=*/true));
 
       KnownBits KnownNSWComputed = KnownBits::computeForAddSub(
           IsAdd, /*NSW=*/true, /*NUW=*/false, Known1, Known2);
-      if (!KnownNSW.hasConflict())
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jayfoad wrote:

This `if` is now unnecessary since I moved the handling of always-poison results into `checkResult`. Same below.

https://github.com/llvm/llvm-project/pull/89585