bug in TestSuite/Mgrid/mgrid.pc

The file TestSuite/Mgrid/mgrid.pc contains the following declarations
(line 266 and on):

  virtual int mx[3]; // (they're the same on all elements, in fact)
  virtual int myproc;
  virtual buff_t sidebuf;
  virtual int start[3], stop[3];
  virtual logical has_neighbor[2][3];
  virtual double rnm2_tmp, rnmu_tmp;

I think this code is illegal and should be changed (ARM 7.1.2: "The
_virtual_ specifier may be used only in declarations of nonstatic class
member functions within a class declaration".).