[PATCH] Rework -fno-omit-frame-pointer support on i386

[Adhemerval Zanella]

>> -#if __GNUC_PREREQ (5,0) && !defined PROF
>> +   profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
>> +   can't be used to put the 6th argument in %ebp for syscall.  */
>> +#if __GNUC_PREREQ (5,0) && !defined PROF && CAN_USE_REGISTER_ASM_EBP
> 
> Should it be "defined CAN_USE_REGISTER_ASM_EBP"
> since CAN_USE_REGISTER_ASM_EBP may not be defined.

In fact since it is defined in config.h.in as default being 0, it will
always be defined (also I check with -O2 and -Os without --disable-werror
to confirm it.

> 
>>  # define OPTIMIZE_FOR_GCC_5
>>  #endif
>>
>> @@ -611,7 +611,8 @@ struct libc_do_syscall_args
>>  #endif
>>
>>  /* Consistency check for position-independent code.  */
>> -#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
>> +#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5 \
>> +    && !CAN_USE_REGISTER_ASM_EBP
> 
> No need for this.  If CAN_USE_REGISTER_ASM_EBP
> isn't defined, OPTIMIZE_FOR_GCC_5 won't be defined.
> 
>>  # define check_consistency()                                                 \
>>    ({ int __res;                                                                      \
>>       __asm__ __volatile__                                                    \
>> --
>> 2.7.4
>>

Right, I will remove it.  I presume with this fix it is ok to commit.