Async I/O patch with compilation fix

[Thomas Koenig]

Hi Christophe,

> Hi,

>> This is done by
>>
>> +#if defined(__GTHREAD_HAS_COND) && defined(__GTHREADS_CXX0X) &&
>> !defined(__ARMEB__)
>> +#define ASYNC_IO 1
>> +#else
>> +#define ASYNC_IO 0
>> +#endif

> I tried this version of the patch, and I'm still seeing the regression
> on array_constructor_8.f90.

Urgh...

Could you run

gcc -dM foo.h

with an empty foo.h in your target environment to see if
__ARMEB__ is actually defined?  If it is not, what other
macro or combination of macros could be used?

At the moment, and with the data you posted in the PR, it seems that
this might be a library problem. Calling different library functions
with or without the patch seems to be an indication of that.

Currently, this patch holds up other major work :-(

What I would propose is to commit the patch as given in
https://gcc.gnu.org/ml/fortran/2018-08/msg00007.html
and open a PR for the strange armeb failure (if the test
for the macros above does not a promising approach).
Let us then fix this PR before the 9.0 release.

Regards

	Thomas