[clang-check][syntax] Crash in TreeBuilder::assignRole: Assertion `It->second->getRole() == NodeRole::Detached && "re-assigning role for a child"' ` failed.

This input is generated by a fuzzer.
```cxx
int foo = F(Y, &str);
```

```
clang-check --tokens-dump example.cpp -- -xc++ -std=c++23
```

Interestingly, if you change `str` into other symbols, it does not crash.

```
clang-check: /home/ubuntu2404/llvm-project-196067/clang/lib/Tooling/Syntax/BuildTree.cpp:589: void clang::syntax::TreeBuilder::Forest::assignRole(llvm::ArrayRef, clang::syntax::NodeRole): Assertion `It->second->getRole() == NodeRole::Detached && "re-assigning role for a child"' failed.
#0 0x0000593f26d2b1f1 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x96d1f1)
#1 0x0000593f26d27dac llvm::sys::RunSignalHandlers() (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x969dac)
#2 0x0000593f26d27f0c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#3 0x00007df212845330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#4 0x00007df21289eb2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
#5 0x00007df21289eb2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10
#6 0x00007df21289eb2c pthread_kill ./nptl/pthread_kill.c:89:10
#7 0x00007df21284527e raise ./signal/../sysdeps/posix/raise.c:27:6
#8 0x00007df2128288ff abort ./stdlib/abort.c:81:7
#9 0x00007df21282881b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#10 0x00007df21283b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
#11 0x0000593f270bfe53 (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xd01e53)
#12 0x0000593f270dab41 (anonymous namespace)::BuildTreeVisitor::TraverseNestedNameSpecifierLoc(clang::NestedNameSpecifierLoc) BuildTree.cpp:0:0
#13 0x0000593f270dc44e clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseDeclRefExpr(clang::DeclRefExpr*, llvm::SmallVectorImpl, llvm::PointerIntPairInfo>>>*) BuildTree.cpp:0:0
#14 0x0000593f270d29be clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseStmt(clang::Stmt*, llvm::SmallVectorImpl, llvm::PointerIntPairInfo>>>*) (.constprop.0) BuildTree.cpp:0:0
#15 0x0000593f270d7d4c clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseUnaryOperator(clang::UnaryOperator*, llvm::SmallVectorImpl, llvm::PointerIntPairInfo>>>*) BuildTree.cpp:0:0
#16 0x0000593f270d29be clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseStmt(clang::Stmt*, llvm::SmallVectorImpl, llvm::PointerIntPairInfo>>>*) (.constprop.0) BuildTree.cpp:0:0
#17 0x0000593f270d7a2d clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseObjCBoxedExpr(clang::ObjCBoxedExpr*, llvm::SmallVectorImpl, llvm::PointerIntPairInfo>>>*) BuildTree.cpp:0:0
#18 0x0000593f270d29be clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseStmt(clang::Stmt*, llvm::SmallVectorImpl, llvm::PointerIntPairInfo>>>*) (.constprop.0) BuildTree.cpp:0:0
#19 0x0000593f270e2dfb clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseVarDecl(clang::VarDecl*) BuildTree.cpp:0:0
#20 0x0000593f270caaea clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseDeclContextHelper(clang::DeclContext*) BuildTree.cpp:0:0
#21 0x0000593f270e383b clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseTranslationUnitDecl(clang::TranslationUnitDecl*) BuildTree.cpp:0:0
#22 0x0000593f270ca439 clang::syntax::buildSyntaxTree(clang::syntax::Arena&, clang::syntax::TokenBufferTokenManager&, clang::ASTContext&) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xd0c439)
#23 0x0000593f267be4af (anonymous namespace)::DumpSyntaxTree::CreateASTConsumer(clang::CompilerInstance&, llvm::StringRef)::Consumer::HandleTranslationUnit(clang::ASTContext&) ClangCheck.cpp:0:0
#24 0x0000593f285f4f9c clang::ParseAST(clang::Sema&, bool, bool) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x2236f9c)
#25 0x0000593f26d82271 clang::FrontendAction::Execute() (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x9c4271)
#26 0x0000593f26dce308 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xa10308)
#27 0x0000593f270aacb7 clang::tooling::FrontendActionFactory::runInvocation(std::shared_ptr, clang::FileManager*, std::shared_ptr, clang::DiagnosticConsumer*) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xceccb7)
#28 0x0000593f270a4b2a clang::tooling::ToolInvocation::runInvocation(char const*, clang::driver::Compilation*, std::shared_ptr, std::shared_ptr) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xce6b2a)
#29 0x0000593f270a71e2 clang::tooling::ToolInvocation::run() (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xce91e2)
#30 0x0000593f270a8e19 clang::tooling::ClangTool::run(clang::tooling::ToolAction*) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xceae19)
#31 0x0000593f26743405 main (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x385405)
#32 0x00007df21282a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#33 0x00007df21282a28b call_init ./csu/../csu/libc-start.c:128:20
#34 0x00007df21282a28b __libc_start_main ./csu/../csu/libc-start.c:347:5
#35 0x0000593f267bd045 _start (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x3ff045)
```

Reproduce the crash with clang-check --tokens-dump on the provided example.cpp command and inspect clang/lib/Tooling/Syntax/BuildTree.cpp around Forest::assignRole at line 589. Trace the nested-name-specifier and DeclRefExpr traversal shown in the stack trace, then verify that the same input no longer triggers the assertion.

Written by the indexing model from the issue text.