AMDGPU: Pass HwMode to AMDGPUGenRegisterInfo (#117449)

I haven't figured out how to do anything useful with this yet,
but it seems you are supposed to pass this to the subtarget
constructor.

Author: arsenm

llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp

@@ -319,7 +319,8 @@ struct SGPRSpillBuilder {
 
 SIRegisterInfo::SIRegisterInfo(const GCNSubtarget &ST)
     : AMDGPUGenRegisterInfo(AMDGPU::PC_REG, ST.getAMDGPUDwarfFlavour(),
-                            ST.getAMDGPUDwarfFlavour()),
+                            ST.getAMDGPUDwarfFlavour(),
+                            /*PC=*/0, ST.getHwMode()),
       ST(ST), SpillSGPRToVGPR(EnableSpillSGPRToVGPR), isWave32(ST.isWave32()) {
 
   assert(getSubRegIndexLaneMask(AMDGPU::sub0).getAsInteger() == 3 &&