[llvm] [JSON][NFC] Support `print` and `dump` methods in `json::Value` (PR #129302)

[Michele Scuttari via llvm-commits]

mscuttari wrote:

@npanchen Having this conditional compilation inside a header file breaks the linking phase in out-of-tree projects which are built in debug mode (that is, with the NDEBUG variable not defined) and at the same time link with a release build of LLVM (that is, with the NDEBUG variable defined).

https://github.com/llvm/llvm-project/pull/129302