[clang] [clang] Preserve UDL nodes in RemoveNestedImmediateInvocation (PR #66641)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

I wonder if `TreeTransform::TransformUserDefinedLiteral()` should be doing something like `RebuildUserDefinedLiteral()`.

Anyways, the patch looks reasonable to me but someone more familiar with Sema should review it.

https://github.com/llvm/llvm-project/pull/66641