...
>> Index: gcc/c-family/c-common.c
>> ===================================================================
>> --- gcc/c-family/c-common.c    (revision 231903)
>> +++ gcc/c-family/c-common.c    (working copy)
>> @@ -7667,6 +7667,6 @@
>>
>>     if (error_operand_p (align))
>>       return -1;
>>     if (TREE_CODE (align) != INTEGER_CST
>>         || !INTEGRAL_TYPE_P (TREE_TYPE (align)))
>>       {
> No changes in this hunk.  I assume you hand-edited the patch to remove
> something that you really didn't intend to submit and left the above
> useless hunk.

That's right.  It doesn't look like Emacs Diff mode is smart
enough to handle these types of edits.  I've removed the hunk
from the updated patch.

> The patch itself is fine for the trunk.

Thanks.  Unfortunately, I had missed a set of important use
cases that are apparently not exercised by the test suite:
__sync_bool_compare_and_swap, __sync_val_compare_and_swap,
__sync_lock_test_and_set, and __sync_lock_release are valid
for _Bool and must not be rejected.

I've corrected the handling of those in the attached patch
and added tests for them.

Martin