[Clang] Fix some assertions not looking through type sugar

Fixes #92284

Author: MitalAshok

clang/lib/AST/ExprConstant.cpp

@@ -11420,7 +11420,7 @@ bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
 
 bool ArrayExprEvaluator::VisitCXXParenListInitExpr(
     const CXXParenListInitExpr *E) {
-  assert(dyn_cast<ConstantArrayType>(E->getType()) &&
+  assert(E->getType()->isConstantArrayType() &&
          "Expression result is not a constant array type");
 
   return VisitCXXParenListOrInitListExpr(E, E->getInitExprs(),

clang/lib/Sema/SemaInit.cpp

@@ -5511,7 +5511,7 @@ static void TryOrBuildParenListInitialization(
           << SE->getSourceRange();
       return;
     } else {
-      assert(isa<IncompleteArrayType>(Entity.getType()));
+      assert(Entity.getType()->isIncompleteArrayType());
       ArrayLength = Args.size();
     }
     EntityIndexToProcess = ArrayLength;

clang/test/SemaCXX/paren-list-agg-init.cpp

@@ -313,3 +313,19 @@ namespace GH63903 {
   constexpr S s(0); // beforecxx20-warning {{aggregate initialization of type 'const S' from a parenthesized list of values is a C++20 extension}} \
                     // expected-error {{constexpr variable 's' must be initialized by a constant expression}}
 }
+
+namespace GH92284 {
+  using T = int[1]; T x(42);
+// beforecxx20-warning@-1 {{aggregate initialization of type 'T' (aka 'int[1]') from a parenthesized list of values is a C++20 extension}}
+  using Ta = int[2]; Ta a(42);
+// beforecxx20-warning@-1 {{aggregate initialization of type 'Ta' (aka 'int[2]') from a parenthesized list of values is a C++20 extension}}
+  using Tb = int[2]; Tb b(42,43);
+// beforecxx20-warning@-1 {{aggregate initialization of type 'Tb' (aka 'int[2]') from a parenthesized list of values is a C++20 extension}}
+  using Tc = int[]; Tc c(42);
+// beforecxx20-warning@-1 {{aggregate initialization of type 'int[1]' from a parenthesized list of values is a C++20 extension}}
+  using Td = int[]; Td d(42,43);
+// beforecxx20-warning@-1 {{aggregate initialization of type 'int[2]' from a parenthesized list of values is a C++20 extension}}
+  template<typename T, int Sz> using ThroughAlias = T[Sz];
+  ThroughAlias<int, 1> e(42);
+// beforecxx20-warning@-1 {{aggregate initialization of type 'ThroughAlias<int, 1>' (aka 'int[1]') from a parenthesized list of values is a C++20 extension}}
+}