[clang-check][syntax] Crash in TreeBuilder::shrinkToFitList: assertion `(EndChildren == Trees.end() || EndChildren->first == Range.end()) && "Range crosses boundaries of existing subtrees"'`

This input is generated by a fuzzer.
This seems to be a crash-on-valid?
```cxx
struct X {} x;
struct S {
void capture(X &x) [[clang::lifetime_capture_by(x)]];
};

```

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

```
clang-check: /home/ubuntu2404/llvm-project-196067/clang/lib/Tooling/Syntax/BuildTree.cpp:603: llvm::ArrayRef clang::syntax::TreeBuilder::Forest::shrinkToFitList(llvm::ArrayRef): Assertion `(EndChildren == Trees.end() || EndChildren->first == Range.end()) && "Range crosses boundaries of existing subtrees"' failed.
#0 0x0000563dc98b21f1 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x96d1f1)
#1 0x0000563dc98aedac llvm::sys::RunSignalHandlers() (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x969dac)
#2 0x0000563dc98aef0c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#3 0x000074e36ce45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#4 0x000074e36ce9eb2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
#5 0x000074e36ce9eb2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10
#6 0x000074e36ce9eb2c pthread_kill ./nptl/pthread_kill.c:89:10
#7 0x000074e36ce4527e raise ./signal/../sysdeps/posix/raise.c:27:6
#8 0x000074e36ce288ff abort ./stdlib/abort.c:81:7
#9 0x000074e36ce2881b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#10 0x000074e36ce3b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
#11 0x0000563dc9c4de60 bool (anonymous namespace)::BuildTreeVisitor::processDeclaratorAndDeclaration(clang::DeclaratorDecl*) BuildTree.cpp:0:0
#12 0x0000563dc9c51aea clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseDeclContextHelper(clang::DeclContext*) BuildTree.cpp:0:0
#13 0x0000563dc9c6795d clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseCXXRecordDecl(clang::CXXRecordDecl*) BuildTree.cpp:0:0
#14 0x0000563dc9c51aea clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseDeclContextHelper(clang::DeclContext*) BuildTree.cpp:0:0
#15 0x0000563dc9c6a83b clang::RecursiveASTVisitor<(anonymous namespace)::BuildTreeVisitor>::TraverseTranslationUnitDecl(clang::TranslationUnitDecl*) BuildTree.cpp:0:0
#16 0x0000563dc9c51439 clang::syntax::buildSyntaxTree(clang::syntax::Arena&, clang::syntax::TokenBufferTokenManager&, clang::ASTContext&) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xd0c439)
#17 0x0000563dc93454af (anonymous namespace)::DumpSyntaxTree::CreateASTConsumer(clang::CompilerInstance&, llvm::StringRef)::Consumer::HandleTranslationUnit(clang::ASTContext&) ClangCheck.cpp:0:0
#18 0x0000563dcb17bf9c clang::ParseAST(clang::Sema&, bool, bool) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x2236f9c)
#19 0x0000563dc9909271 clang::FrontendAction::Execute() (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x9c4271)
#20 0x0000563dc9955308 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xa10308)
#21 0x0000563dc9c31cb7 clang::tooling::FrontendActionFactory::runInvocation(std::shared_ptr, clang::FileManager*, std::shared_ptr, clang::DiagnosticConsumer*) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xceccb7)
#22 0x0000563dc9c2bb2a clang::tooling::ToolInvocation::runInvocation(char const*, clang::driver::Compilation*, std::shared_ptr, std::shared_ptr) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xce6b2a)
#23 0x0000563dc9c2e1e2 clang::tooling::ToolInvocation::run() (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xce91e2)
#24 0x0000563dc9c2fe19 clang::tooling::ClangTool::run(clang::tooling::ToolAction*) (/home/ubuntu2404/build-196067-assert/bin/clang-check+0xceae19)
#25 0x0000563dc92ca405 main (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x385405)
#26 0x000074e36ce2a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#27 0x000074e36ce2a28b call_init ./csu/../csu/libc-start.c:128:20
#28 0x000074e36ce2a28b __libc_start_main ./csu/../csu/libc-start.c:347:5
#29 0x0000563dc9344045 _start (/home/ubuntu2404/build-196067-assert/bin/clang-check+0x3ff045)
Aborted (core dumped)
```

Reproduce the crash with the provided C++ input and clang-check command, then inspect clang/lib/Tooling/Syntax/BuildTree.cpp around shrinkToFitList at line 603 and the BuildTreeVisitor call path shown in the trace. Done means the input no longer triggers the assertion when clang-check runs with --tokens-dump and -std=c++23.

Written by the indexing model from the issue text.