Ah! I finally have a progress bar that doesn't stall the build!
- pipe size in Linux is only 8*512=4096 bytes
- pipe size is not setable
- when the feeding process spits out data faster than the eating
process can read it, then the feeding process stalls after 4KiB
of data sent to the pipe
- for us, the progress bar would spawn a sub-shell every line,
and the sub-shell would in turn spawn a 'date' command.
Which was sloooww as hell, and would cause some kind of a
starvation: the pipe was full most of the time, and the
feeding process was stalled all this time.

Now, we use internal variables and a little hack based onan offset
to determine the elapsed time. Much faster this way, but still
CPU-intensive.

 See http://sources.redhat.com/ml/binutils/2004-06/msg00114.html

 --- src/bfd/elflink.c.org	2004-07-05 09:11:42.920597000 -0400

 +++ src/bfd/elflink.c	2004-07-05 09:12:59.240847000 -0400

 @@ -2700,7 +2700,7 @@

      return vdiff > 0 ? 1 : -1;

    else

      {

 -      long sdiff = h1->root.u.def.section - h2->root.u.def.section;

 +      long sdiff = h1->root.u.def.section->id - h2->root.u.def.section->id;

        if (sdiff != 0)

  	return sdiff > 0 ? 1 : -1;

      }

 @@ -3954,7 +3954,7 @@

  		i = idx + 1;

  	      else

  		{

 -		  long sdiff = slook - h->root.u.def.section;

 +		  long sdiff = slook->id - h->root.u.def.section->id;

  		  if (sdiff < 0)

  		    j = idx;

  		  else if (sdiff > 0)