At present, pubnames are not emitted when -freorder-blocks-and- 
partition is active.

This causes debug linking to fail on Darwin.

The following patch outputs code ranges for Dwarf >=3 and produces a  
work-around for Dwarf-2.

With this patch [and the one in http://gcc.gnu.org/ml/gcc-patches/2010-12/msg01553.html 
] we can re-enable -freorder-blocks-and-partition on Darwin and debug  
works (at least for the partition cases in the test-suite).

OK for trunk?
Iain

gcc:

	* dwarf2out.c (gen_subprogram_die):  Add pubnames with code ranges for
	DWARF >= 3.  Add pubnames for the primary section and a reduced DIE for
	the secondary code fragment when outputting for DWARF == 2.