[clang] [clang] Add 'instantiated_from' for enums to the output of TextNodeDumper (PR #124409)

[André Brand via cfe-commits]

thebrandre wrote:

@shafik @Sirraide I rechecked everything and I fixed some non-relative line numbers. I only just noticed now that I probably should have checked that by inserting some line numbers just before my test code to see if this doesn't break the test. 🙈

If there is still something wrong/bad practice/etc. in the test, I'd be grateful for any advice on how to improve it. 😊

https://github.com/llvm/llvm-project/pull/124409