[llvm] [AMDGPU] MCExpr printing helper with KnownBits support (PR #95951)

[Pierre van Houtryve via llvm-commits]

================
@@ -303,3 +305,360 @@ const AMDGPUMCExpr *AMDGPUMCExpr::createOccupancy(unsigned InitOcc,
                  CreateExpr(InitOcc), NumSGPRs, NumVGPRs},
                 Ctx);
 }
+
+static KnownBits fromOptionalToKnownBits(std::optional<bool> CompareResult) {
+  const unsigned BitWidth = 64;
+  const APInt True(BitWidth, 1, /*isSigned=*/false);
+  const APInt False(BitWidth, 0, /*isSigned=*/false);
+  if (CompareResult) {
+    return *CompareResult ? KnownBits::makeConstant(True)
+                          : KnownBits::makeConstant(False);
----------------
Pierre-vh wrote:

```suggestion
    return KnownBits::makeConstant(*CompareResult); 
```

https://github.com/llvm/llvm-project/pull/95951