[clang] Fix a crash in debug mode

Resolves Issue #35603

This bug was caused due to the assertions being too strict,
loosened by stripping qualifiers from the base class but not
from the type of the initializer.

Added Release Notes for the same.

Author: Rajveer100

clang/docs/ReleaseNotes.rst

@@ -918,6 +918,9 @@ Bug Fixes to C++ Support
   (`#57410 <https://github.com/llvm/llvm-project/issues/57410>`_) and
   (`#76604 <https://github.com/llvm/llvm-project/issues/57410>`_)
 
+- Fix crash when inheriting from a cv-qualified type. Fixes:
+  (`#35603 <https://github.com/llvm/llvm-project/issues/35603>`_)
+
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 - Fixed an import failure of recursive friend class template.

clang/lib/AST/ExprConstant.cpp

@@ -6417,7 +6417,7 @@ static bool HandleConstructorCall(const Expr *E, const LValue &This,
       // Non-virtual base classes are initialized in the order in the class
       // definition. We have already checked for virtual base classes.
       assert(!BaseIt->isVirtual() && "virtual base for literal type");
-      assert(Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&
+      assert(Info.Ctx.hasSameUnqualifiedType(BaseIt->getType(), BaseType) &&
              "base class initializers not in expected order");
       ++BaseIt;
 #endif

clang/test/Sema/GH35603.cpp

@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++11 %s -verify
+// RUN: %clang_cc1 -fsyntax-only -std=c++23 %s -verify
+
+// expected-no-diagnostics
+
+struct A {};
+using CA = const A;
+
+struct S1 : CA {
+  constexpr S1() : CA() {}
+};
+
+struct S2 : A {
+  constexpr S2() : CA() {}
+};
+
+struct S3 : CA {
+  constexpr S3() : A() {}
+};