[Bug middle-end/83764] internal compiler error: in gimple_get_virt_method_for_vtable

[lesliezhai at llvm dot org.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83764

--- Comment #2 from Leslie Zhai <lesliezhai at llvm dot org.cn> ---
And GCC 8.x workaround just remove the assert:

6751   /* The virtual tables should always be born with constructors            
6752      and we always should assume that they are avaialble for               
6753      folding.  At the moment we do not stream them in all cases,           
6754      but it should never happen that ctor seem unreachable.  */            
6755   gcc_assert (init);                                                       
6756   if (init == error_mark_node)                                             
6757     {                                                                      
6758       /* Pass down that we lost track of the target.  */                   
6759       if (can_refer)                                                       
6760     *can_refer = false;                                                    
6761       return NULL_TREE;                                                    
6762     }