Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* contrib/cc-with-tweaks.sh: Add -p parameter to invoke dwp.
* dwarf2read.c: #include "elf-bfd.h".
(struct dwarf2_per_objfile): New members dwp_checked, dwp_file.
(dwop_section_names): Renamed from dwo_section names. All uses
updated. Add entries for .debug_cu_index, .debug_tu_index.
(struct dwo_file): Rename dwo_name to name, dwo_bfd to dbfd.
All uses updated.
(struct dwp_sections): New type.
(struct virtual_dwo_sections): New type.
(struct dwp_hash_table): New type.
(struct dwp_file): New type.
(init_cutu_and_read_dies): Ensure DWO info/types section has been
read in. Handle DWOs coming from DWP files.
(lookup_dwo_file_slot): New function.
(dwarf2_locate_dwo_sections): Move definition closer to use.
(create_dwo_debug_info_hash_table_reader): Renamed from
create_debug_info_hash_table_reader. All callers updated.
(create_dwo_debug_info_hash_table): Renamed from
create_debug_info_hash_table. All callers updated.
(create_dwp_hash_table): New function.
(locate_virtual_dwo_sections, create_dwo_in_dwp): New functions.
(lookup_dwo_in_dwp): New function.
(try_open_dwop_file): Renamed from try_open_dwo_file. New parameter
is_dwp. All callers updated.
(open_dwop_file): Renamed from open_dwo_file. All callers updated.
(open_and_init_dwo_file): Renamed from init_dwo_file.
All callers updated.
(lookup_dwo_file): Delete.
(dwarf2_locate_dwp_sections): New function.
(hash_dwp_loaded_cutus, eq_dwp_loaded_cutus): New functions.
(allocate_dwp_loaded_cutus_table): New function.
(open_and_init_dwp_file): New function.
(lookup_dwo_cutu): New function.
(lookup_dwo_comp_unit, lookup_dwo_type_unit): Call it.