[clang][dataflow] fix bug for transparent ListInitExpr handling

This fixes the handling of "transparent" ListInitExpr, when they're only
used as a copy constructor for records.

Without the fix, the two tests are crashing the process.

clang/lib/Analysis/FlowSensitive/Transfer.cpp

@@ -637,6 +637,13 @@ class TransferVisitor : public ConstStmtVisitor<TransferVisitor> {
       return;
     }
 
+    // In case the initializer list is transparent, we just need to propagate
+    // the value that it contains.
+    if (S->isSemanticForm() && S->isTransparent()) {
+      propagateValue(*S->getInit(0), *S, Env);
+      return;
+    }
+
     std::vector<FieldDecl *> Fields =
         getFieldsForInitListExpr(Type->getAsRecordDecl());
     llvm::DenseMap<const ValueDecl *, StorageLocation *> FieldLocs;

clang/unittests/Analysis/FlowSensitive/TransferTest.cpp

@@ -2183,6 +2183,39 @@ TEST(TransferTest, CopyConstructorWithParens) {
       });
 }
 
+TEST(TransferTest, CopyConstructorWithInitializerListAsSyntacticSugar) {
+  std::string Code = R"(
+  struct A {
+    int Baz;
+  };
+  void target() {
+    A Foo = {3};
+    (void)Foo.Baz;
+    A Bar = {A(Foo)};
+    // [[p]]
+  }
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {
+        const Environment &Env = getEnvironmentAtAnnotation(Results, "p");
+
+        const ValueDecl *BazDecl = findValueDecl(ASTCtx, "Baz");
+
+        const auto &FooLoc =
+            getLocForDecl<AggregateStorageLocation>(ASTCtx, Env, "Foo");
+        const auto &BarLoc =
+            getLocForDecl<AggregateStorageLocation>(ASTCtx, Env, "Bar");
+
+        const auto *FooBazVal =
+            cast<IntegerValue>(getFieldValue(&FooLoc, *BazDecl, Env));
+        const auto *BarBazVal =
+            cast<IntegerValue>(getFieldValue(&BarLoc, *BazDecl, Env));
+        EXPECT_EQ(FooBazVal, BarBazVal);
+      });
+}
+
 TEST(TransferTest, CopyConstructorArgIsRefReturnedByFunction) {
   // This is a crash repro.
   std::string Code = R"(