Fix bound checking dlcose problem

Fix bound checking dlcose problem

The main problem is that an application called dlclose and then
had a bound checking problem. The list of dll's in tccrun was
not updated an caused a crash.
Also fixed some minor other things.

tccdbg.c:
- Allow filenames like ../file.c
- Rewrite DWARF_ABBREV_MEMBER_BF/DWARF_ABBREV_MEMBER a bit

tccelf.c:
- Add call to __bt_exit. This solves problem when dlclose is called

tccrun.c:
- Rewrite rt_printline_dwarf a litlle to use opcode_length correctly
- Do not stop at DW_LNE_end_sequence
- Fix DW_LNE_set_address again. Works now in *bsd.

lib/bt-exe.c lib/bt-dll.c:
- Add __bt_exit/__bound_exit_dll

lib/bcheck.c:
- Add __bound_exit_dll