[clang] [AST] Assert that FoldingSetNodeID used for hint is correct upon insertion (PR #157692)

[Ilya Biryukov via cfe-commits]

ilya-biryukov wrote:

+1 for the inline helper. But if we go down that path, maybe we could add an optional parameter to `InsertNode` and make it the helper we're talking about?

```cpp
[[always_inline]] Ret InsertNode(<args>, llvm::FoldingSetNodeID* IDForAssert = nullptr) {
  assert(!IDForAssert || IDForAssert == ...);
  return InsertNodeImpl(<args>);
}
```

https://github.com/llvm/llvm-project/pull/157692