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

[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,
----------------
ruiling wrote:

BTW, the function was only passed the `base` part, I have added the whole address as well as the base.

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