[llvm] [BasicBlockSections] Using MBBSectionID as DenseMap key (PR #97295)

[Rahman Lavaee via llvm-commits]

rlavaee wrote:

Sorry, I was OOO and didn't get a chance to look at this. You mention that `A Cold type MBBSectionID with number 0 and a Default type MBBSectionID with number 2 get same value 2 from getSectionIDNum`, but I think the former will get 0 and the will get 2.  Am I missing anything?

https://github.com/llvm/llvm-project/pull/97295