Patch to gfortran PR13742

[Victor Leikehman]

Paul Brook wrote:

> From section 5.5.2.4 "Differences between named common and blank common"
> 
> "(3) A data object in a named common block may be initially defined by means 
> of a DATA statement [...] objects in a blank common may not be initially 
> defined."

Oops. I will revise and resubmit the patch.

Thanks to all reviewers!
	Victor