[RFA] Nullified garbage-collected global variables

[Tom Tromey]

>>>>> "Jerome" == Jerome Guitton <guitton@adacore.com> writes:

Jerome> 	* dwarf2read.c (add_partial_symbol): Do not add a global variable if
Jerome> 	its adress is null. Add comment to explain why.

I am not totally sure about this.  The patch itself looks reasonable,
but I have a couple of questions.

Do you need to apply the same treatment to full symbols?  What happens
if the psymtab is expanded for some other reason and a full symbol of
this sort is then created?  Or is that already impossible?

What about has_section_at_zero?

Tom