Simplify arithmetic operations on registry and memory

[pedrobsaila]

Fixes #125300

Lacks tests, working on it

Before :

Program:AddReg(int):int (FullOpts):
       lea      eax, [rdi+2*rdi]
       ret      

Program:AddMem(byref):int (FullOpts):
       mov      eax, dword ptr [rdi]
       lea      ecx, [rax+rax]
       add      eax, ecx
       ret      

Program:SubReg(int):int (FullOpts):
       xor      eax, eax
       sub      eax, edi
       ret      

Program:SubMem(byref):int (FullOpts):
       mov      eax, dword ptr [rdi]
       mov      ecx, eax
       sub      ecx, eax
       sub      ecx, eax
       mov      eax, ecx
       ret  

After:

Program:AddReg(int):int (FullOpts):
       lea      eax, [rdi+2*rdi]
       ret      

Program:AddMem(byref):int (FullOpts):
       mov      eax, dword ptr [rdi]
       lea      eax, [rax+2*rax]
       ret      

Program:SubReg(int):int (FullOpts):
       mov      eax, ecx
       neg      eax
       ret      

Program:SubMem(byref):int (FullOpts):
       mov      eax, dword ptr [rdi]
       neg      eax
       ret 

[dotnet-policy-service]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.