Add end_psymtab_common, have all debug info readers call it.
gdb/ChangeLog:
* dbxread.c (dbx_end_psymtab): Renamed from end_psymtab. All callers
updated. Call end_psymtab_common.
* dwarf2read.c (process_psymtab_comp_unit_reader): Call
end_psymtab_common.
(build_type_psymtabs_reader): Ditto.
* psympriv.h (sort_pst_symbols): Delete.
(end_psymtab_common): Declare.
* psymtab.c (sort_pst_symbols): Make static.
(end_psymtab_common): New function.
* xcoffread.c (xcoff_end_psymtab): Call end_psymtab_common.