Fix PR67639

[Bernd Schmidt]

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?


Bernd