[llvm] [AMDGPU] Folding imm offset in more cases for scratch access (PR #70634)

[Matt Arsenault via llvm-commits]

================
@@ -1146,10 +1146,23 @@ bool AMDGPUDAGToDAGISel::isDSOffset2Legal(SDValue Base, unsigned Offset0,
   return CurDAG->SignBitIsZero(Base);
 }
 
-bool AMDGPUDAGToDAGISel::isFlatScratchBaseLegal(SDValue Base,
+bool AMDGPUDAGToDAGISel::isFlatScratchBaseLegal(SDValue Addr, SDValue Base,
----------------
arsenm wrote:

Should also make the analogous GlobalISel change 

https://github.com/llvm/llvm-project/pull/70634