[gfortran] patch for pr libfortran/21303

[Jerry DeLisle]

FX Coudert wrote:
>> Attached proposed patch fixes PR libfortran/21303, which is about 
>> allowing (as an extension) a L format descriptor to have no width 
>> specified (in which case, the width is taken to be 1). It adds a few 
>> standard checking routines that do not issue an error/warning, as the 
>> front-end format checking error handling doesn't mix well with 
>> gfc_notify_std. It adds the same thing into the library for runtime 
>> warnings/errors.
>>
>> Regtested on i686-linux. OK for trunk?
> 
> 
> ping
> 
> 
FX,

Now that I can, I will review in the next day or so.

Jerry