[llvm] [AArch64][GISel] Separate legalize actions for G_FREEZE from G_IMPLICIT_DEF (PR #88469)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> These was a lot less implemented back then, and it was easier to implement one piece at a time. Intrinsically, these should have the same rules.

This commit is so old, I'm not sure freeze was even in the IR yet 

https://github.com/llvm/llvm-project/pull/88469