[C++20] [Modules] Handling capturing strucuted bindings

Close #72828.

This should be an overlook that we extend the type of captures but we
forgot to fix it in deserializer side.

Author: ChuanqiXu9

clang/lib/Serialization/ASTReaderDecl.cpp

@@ -2032,7 +2032,7 @@ void ASTDeclReader::ReadCXXDefinitionData(
         break;
       case LCK_ByCopy:
       case LCK_ByRef:
-        auto *Var = readDeclAs<VarDecl>();
+        auto *Var = readDeclAs<ValueDecl>();
         SourceLocation EllipsisLoc = readSourceLocation();
         new (ToCapture) Capture(Loc, IsImplicit, Kind, Var, EllipsisLoc);
         ToCapture++;

clang/test/Modules/pr72828.cppm

@@ -0,0 +1,24 @@
+// Test that we can handle capturing structured bindings.
+//
+// RUN: rm -fr %t
+// RUN: mkdir %t
+//
+// RUN: %clang_cc1 -std=c++23 -triple %itanium_abi_triple \
+// RUN:     %s -emit-module-interface -o %t/m.pcm
+// RUN: %clang_cc1 -std=c++23 -triple %itanium_abi_triple \
+// RUN:     -S -emit-llvm -disable-llvm-passes %t/m.pcm \
+// RUN:     -o - | FileCheck %s
+
+export module m;
+
+struct s {
+	int m;
+};
+
+void f() {
+	auto [x] = s();
+	[x] {};
+}
+
+// Check that we can generate the LLVM IR expectedly.
+// CHECK: define{{.*}}@_ZGIW1m