Fix bug in type desugaring.

Author: katzdm

clang/lib/AST/APValue.cpp

@@ -1573,9 +1573,9 @@ LinkageInfo LinkageComputer::getLVForValue(const APValue &V,
 }
 
 static QualType unwrapReflectedType(QualType QT) {
-  bool UnwrapAliases = false;
   bool IsConst = QT.isConstQualified();
   bool IsVolatile = QT.isVolatileQualified();
+  bool UnwrapAliases = (IsConst || IsVolatile);
 
   void *AsPtr;
   do {

clang/test/Reflection/info-equality.cpp

@@ -108,6 +108,7 @@ static_assert(^^int != ^^unsigned int);
 static_assert(^^int != ^^Enum);
 static_assert(^^int != ^^EnumCls);
 static_assert(^^int_alias != ^^int);
+static_assert(^^int_alias const == ^^int const);
 static_assert(^^int_alias != ^^Test::type);
 static_assert(^^int_alias != ^^myns::Test::type);
 static_assert(^^Test::type != ^^myns::Test::type);

libcxx/test/std/experimental/reflection/to-and-from-values.pass.cpp

@@ -214,13 +214,11 @@ struct S{};
 
 using Alias1 = int;
 constexpr Alias1 a1 = 3;
-static_assert(type_of(^^a1) != ^^const Alias1);
 static_assert(type_of(^^a1) == ^^const int);
 static_assert(type_of(value_of(^^a1)) == ^^int);
 
 using Alias2 = S;
 constexpr Alias2 a2 {};
-static_assert(type_of(^^a2) != ^^const Alias2);
 static_assert(type_of(^^a2) == ^^const S);
 static_assert(type_of(value_of(^^a2)) == ^^const S);