[llvm] Add unit tests for size returning new funcs in the MemProf use pass. (PR #105473)

[Snehasish Kumar via llvm-commits]

snehasish wrote:

I'll revert for now (https://github.com/llvm/llvm-project/pull/106114) and test with ld.gold before I resubmit. 

https://github.com/llvm/llvm-project/pull/105473