Fix PR67639

[Jeff Law]

On 02/08/2016 07:26 AM, Bernd Schmidt wrote:
> On 12/21/2015 08:39 PM, Jeff Law wrote:
>> On 12/18/2015 11:38 AM, Bernd Schmidt wrote:
>>> In an earlier fix, the following change was made in varasm.c for invalid
>>> register variables:
>>>
>>> --- trunk/gcc/varasm.c    2014/08/26 14:59:59    214525
>>> +++ trunk/gcc/varasm.c    2014/08/26 17:06:31    214526
>>> @@ -1371,6 +1371,11 @@ make_decl_rtl (tree decl)
>>>         /* As a register variable, it has no section.  */
>>>         return;
>>>       }
>>> +      /* Avoid internal errors from invalid register
>>> +     specifications.  */
>>> +      SET_DECL_ASSEMBLER_NAME (decl, NULL_TREE);
>>> +      DECL_HARD_REGISTER (decl) = 0;
>>> +      return;
>>>       }
>>>
>>> As seen in PR67639, this makes the IL inconsistent and triggers another
>>> internal error where we expect to see an SSA_NAME instead of a VAR_DECL.
>>>
>>> The following patch extends the above slightly, by also setting
>>> DECL_EXTERNAL to pretend that the erroneous variable is actually a
>>> global.
>>>
>>> Bootstrapped and tested on x86_64-linux, ok?
>> OK.
>
> Turns out 65702 is a dup and this should go into gcc-5 as well. Ok to
> backport?
Yes.

Thanks,
jeff