Description of problem:

-g3 compilation of a file with no defns (but with some macros) produces a nonempty .debug_macinfo section but an empty .debug_info section.


Version-Release number of selected component (if applicable):
gcc-4.3.2-7.x86_64

How reproducible:
100%

Steps to Reproduce:
1. echo '#define foo bar' > g3.c
2. gcc -c -g3 g3.c
3. readelf --debug-dump={info,macro} g3.o
  
Actual results:

Empty .debug_info section.

Expected results:

.debug_info should get a compile_unit that has the basic attrs (producer, comp_dir, name) and the line and macro table pointers.  .debug_line should contain a file table even with no line entries, both for the include dirs info and for the macro table to point at.

Additional info:

It's fine to fix this only in 4.4, I think.