[clang] [clang] Rework `hasBooleanRepresentation`. (PR #136038)

[Aaron Ballman via cfe-commits]

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@@ -8623,6 +8624,13 @@ inline bool Type::isIntegralOrEnumerationType() const {
 inline bool Type::isBooleanType() const {
   if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
     return BT->getKind() == BuiltinType::Bool;
+  if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
+    // Incomplete enum types are not treated as integer types.
+    // FIXME: In C++, enum types are never integer types.
+    return IsEnumDeclComplete(ET->getDecl()) &&
+           !IsEnumDeclScoped(ET->getDecl()) &&
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AaronBallman wrote:

Why does the the enum being scoped matter?

https://github.com/llvm/llvm-project/pull/136038