[clang] [analyzer] Preserve LocAsInteger through identity operations (PR #225048)

[Peiqi Li via cfe-commits]

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@@ -491,6 +510,11 @@ SVal SimpleSValBuilder::evalBinOpNN(ProgramStateRef state,
                            rhs.castAs<nonloc::LocAsInteger>().getLoc(),
                            resultTy);
       case nonloc::ConcreteIntKind: {
+        // Preserve the location for identity operations.
+        if (isIdentityOperation(op,
+                                rhs.castAs<nonloc::ConcreteInt>().getValue()))
+          return evalCast(lhs, resultTy, QualType{});
+
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voyager-jhk wrote:

The swapped commutative cases are already handled by `evalBinOpNN`, which canonicalizes the operands before reaching this case. `0 + value` and `0 | value` therefore work as well.

https://github.com/llvm/llvm-project/pull/225048