aco/ra: Assert operands only clear their own id

This is useful for debugging register assignment, as this case would
usually result in RA silently assigning the same register to multiple
temps at the same time.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29576>

src/amd/compiler/aco_register_allocation.cpp

@@ -367,7 +367,12 @@ public:
       }
    }
 
-   void clear(Operand op) { clear(op.physReg(), op.regClass()); }
+   void clear(Operand op)
+   {
+      if (op.isTemp() && !is_empty_or_blocked(op.physReg()))
+         assert(get_id(op.physReg()) == op.tempId());
+      clear(op.physReg(), op.regClass());
+   }
 
    void fill(Definition def)
    {