[AMDGPU] Handle MachineOperandType global address in SIFoldOperands.

While FoldingImmLike accepts :
MO_Immediate, MO_FrameIndex and MO_GlobalAddress.
The conditional block after it only covers the first 2.
So I have added a case for the global value as well.

Author: isakhilesh

llvm/lib/Target/AMDGPU/SIFoldOperands.cpp

@@ -1159,6 +1159,8 @@ void SIFoldOperandsImpl::foldOperand(
 
         UseMI->setDesc(TII->get(AMDGPU::S_MOV_B32));
 
+        if (OpToFold.isGlobal())
+          return;
         if (OpToFold.isImm())
           UseMI->getOperand(1).ChangeToImmediate(OpToFold.getImm());
         else