[clang] [clang] Adds a RecursiveASTEnterExitVisitor data type (PR #136136)

[Christopher Taylor via cfe-commits]

ct-clmsn wrote:

@Sirraide thank you for the quality control check; I wasn't aware of `DynamicRecursiveASTVisitor` or the `dataTraverseStmtPre()/dataTraverseStmtPost()` methods. Still catching up to where the community is currently. I'll close out the PR.

https://github.com/llvm/llvm-project/pull/136136