[clang] [clang][bytecode] Implement support for `Expr::EvaluateWithSubstitution()` (PR #204781)

[Alexis Engelke via cfe-commits]

aengelke wrote:

Note that the new DynamicRecursiveASTVisitor adds ~1k relocations and increases .data.rel.ro by a bit over 8 kiB/[0.4% (c-t-t)](https://llvm-compile-time-tracker.com/compare.php?from=45974112fd727b41fe3c4381b94392c1e7fbdd36&to=02de6f8ffed5ff3dae0ac01e526ede69dbdc8caa&stat=size-data).

https://github.com/llvm/llvm-project/pull/204781