[llvm] [AArch64][GISel] Avoid scalarizing G_IMPLICIT_DEF and G_FREEZE in the Legalizer (PR #88469)

[Dhruv Chawla via llvm-commits]

dc03-work wrote:

Pre-commit failures look unrelated to the PR - from what I can see MSVC is running out of memory while building flang and it is crashing there.

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