[llvm] [CodeGen][NewPM] Port `LiveIntervals` to new pass manager (PR #98118)

[Arthur Eubanks via llvm-commits]

================
@@ -50,445 +51,492 @@ class raw_ostream;
 class TargetInstrInfo;
 class VirtRegMap;
 
-  class LiveIntervals : public MachineFunctionPass {
----------------
aeubanks wrote:

can you split out the formatting change and submit that one first?

https://github.com/llvm/llvm-project/pull/98118