[clang] [NFC][analyzer] Eliminate NodeBuilder from ExprEngine visit methods and from their utility methods (PR #212186)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat commented:

Thanks for this cleanup!

The lines that you changed look functionally correct, although I didn't exhaustively check the lines that you didn't touch for branches (especially tricky early return branches) that you should have touched.

I also added many inline comments about opportunities for additional simplifications.

https://github.com/llvm/llvm-project/pull/212186