Removed the assert that the instruction that $noreg is part of has to be a debug inst

Author: adam-yang

llvm/lib/Target/AMDGPU/SIPreAllocateWWMRegs.cpp

@@ -130,10 +130,8 @@ void SIPreAllocateWWMRegs::rewriteRegs(MachineFunction &MF) {
         if (VirtReg.isPhysical())
           continue;
 
-        if (!VirtReg.isValid()) {
-          assert(MI.isDebugInstr() && "non-debug use of noreg");
+        if (!VirtReg.isValid())
           continue;
-        }
 
         if (!VRM->hasPhys(VirtReg))
           continue;