[clang] [Clang] Introduce OverflowBehaviorType for fine-grained overflow control (PR #148914)

[Justin Stitt via cfe-commits]

================
@@ -14308,6 +14455,12 @@ static QualType getCommonNonSugarTypeNode(const ASTContext &Ctx, const Type *X,
         getCommonTypeKeyword(NX, NY, /*IsSame=*/true),
         getCommonQualifier(Ctx, NX, NY, /*IsSame=*/true), NX->getIdentifier());
   }
+  case Type::OverflowBehavior: {
+    // FIXME: Should we consider both types?
+    const auto *NX = cast<OverflowBehaviorType>(X);
+    return Ctx.getOverflowBehaviorType(NX->getBehaviorKind(),
+                                       NX->getUnderlyingType());
----------------
JustinStitt wrote:

fixed in fixed with [`04af8bf`](https://github.com/llvm/llvm-project/pull/148914/commits/04af8bf6e9620c71673a435d3b2eebccd7db3682) but instead of implementing `getCommonUnderlyingType` I went with a recursive call to `getCommonNonSugarTypeNode()`.

https://github.com/llvm/llvm-project/pull/148914