Fix warn-shadow-in-lambdas test for structured bindings

Author: ivanmurashko

clang/test/SemaCXX/warn-shadow-in-lambdas.cpp

@@ -258,9 +258,15 @@ struct S {
 };
 
 int foo() {
+#ifdef AVOID
   auto [a] = S{0}; // cxx14-warning {{decomposition declarations are a C++17 extension}}
-  [a = a] () { // No warning - consistent with regular parameter captures
+  [a = a] () { // No warning with basic -Wshadow due to uncaptured-local classification
+  }();
+#else
+  auto [a] = S{0}; // cxx14-warning {{decomposition declarations are a C++17 extension}} expected-note {{previous declaration is here}}
+  [a = a] () { // expected-warning {{declaration shadows a structured binding}}
   }();
+#endif
 }
 
 }