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

[Aaron Ballman via cfe-commits]

================
@@ -2336,16 +2336,9 @@ bool Type::isArithmeticType() const {
 }
 
 bool Type::hasBooleanRepresentation() const {
-  if (isBooleanType())
-    return true;
-
-  if (const EnumType *ET = getAs<EnumType>())
-    return ET->getDecl()->getIntegerType()->isBooleanType();
-
-  if (const AtomicType *AT = getAs<AtomicType>())
-    return AT->getValueType()->hasBooleanRepresentation();
-
-  return false;
+  if (const auto *VT = dyn_cast<VectorType>(CanonicalType))
----------------
AaronBallman wrote:

Sure, that's what I was trying to understand. An enumeration whose underlying type is bool and a bool have the same representation as an i1. So does `unsigned _BitInt(1)`, so does that have a boolean representation?

("representation" is what is throwing me off.)

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