RFC: Support DW_TAG_entry_point

[Joel Brobecker]

> > Assuming this is an extension, I would like a comment to that effect,
> > mentioning the compiler. Â A test case wouldn't hurt, either.
> >
> 
> I do have a testcase. But you need ifort to use it.

We have a gdb.dwarf2 section where you can provide hard-coded dwarf2
data. That would be very helpful in making sure that we don't break
GDB with ifort's output later on.

-- 
Joel