[llvm] [TableGen][GISel] Learn to import patterns with physreg defs (PR #120343)

[Matt Arsenault via llvm-commits]

arsenm wrote:

I'd expect an arbitrary copy from a physical register to be copied to/from a virtual register with class getMinimalPhysRegClass (or whatever the equivalent is in CodeGenRegisters).
. I'd expect the generated table to use the constrain 



https://github.com/llvm/llvm-project/pull/120343