[llvm] [NFC][LLVM][DSE] Extract large member functions out of class definition (PR #162320)

[Rahul Joshi via llvm-commits]

jurahul wrote:

I wanted to see what your take is here. I find that large inlined functions hinder readability of the code by coming in the way of getting an overall picture of a class (by looking at the class declaration). Having them separated out helps get the impl details outr of the way when trying to get this high-level overview and also eliminated the added indentation when the functions are defined inline.

https://github.com/llvm/llvm-project/pull/162320