windows-nat.c: Bring comment back regarding handling of DLL load events.

This patch brings back a comment that got stripped down a bit too much
during a recent change.

gdb/ChangeLog:

        * windows-nat.c (handle_unload_dll): Add function documentation.
        (do_initial_windows_stuff): Add comment explaining why we wait
        until after inferior initialization has finished before
        processing all DLLs.
Fix PR symtab/16581

	* dwarf2read.c (struct die_info): New member in_process.
	(reset_die_in_process): New function.
	(process_die): Set it at the start, reset when returning.
	(inherit_abstract_dies): Only call process_die if origin_child_die
	not already being processed.

	testsuite/
	* gdb.dwarf2/dw2-icycle.S: New file.
	* gdb.dwarf2/dw2-icycle.c: New file.
	* gdb.dwarf2/dw2-icycle.exp: New file.
fix whitespace in previous commit
Move containing_scm arg from gdbscm_fill_eqable_gsmob_ptr_slot
to gdbscm_init_eqable_gsmob.

	* guile/scm-gsmob.c (gdbscm_init_eqable_gsmob): New arg containing_scm.
	All callers updated.
	(gdbscm_fill_eqable_gsmob_ptr_slot): Delete arg containing_scm.
	All callers updated.
	* guile/guile-internal.h (gdbscm_init_eqable_gsmob): Update.
	(gdbscm_fill_eqable_gsmob_ptr_slot): Update.
Simplify .section in dw2-icycle.S

The arm-elf assembler chokes on the extra parameters in the .section
pseudo-op, so this patch removes them.

gdb/testsuite/ChangeLog:

        * gdb.dwarf2/dw2-icycle.S: Remove second and third parameters
        in .section pseudo-op.
* inferiors.c (get_first_inferior): Fix buglet.
minor cleanup in dbxread.c

I happened to notice that last_o_file_start is write-only in
read_dbx_symtab.  This patch removes it.  Tested by rebuilding.

2014-02-20  Tom Tromey  <tromey@redhat.com>

	* dbxread.c (read_dbx_symtab): Remove last_o_file_start.