tccgen.c:
- add anon support. So tcc_state in tcc works now.
- add function pointer support
- remove DW_FORM_implicit_const from DW_TAG_pointer_type
tccrun.c:
- set initial file name
- correctly use pc in DW_LNE_set_address (see lib/bt-exe.c)
- add DW_LNE_define_file support (even if it is deprecated)
tccelf.c
- do not include debug/test_coverage information for stub functions
lib/bt-exe.c
- use num_callers=-1 to mark dll