gdb/

gdb/
	* dwarf2read.c (file_file_name): New function with code from
	file_full_name.
	(file_full_name): Move most of the code to file_file_name.
	(macro_start_file): Rename variable full_name to file_name and use
	file_file_name for it.  Add comp_dir parameter to new_macro_table.
	* macrocmd.c (show_pp_source_pos): New variable fullname.  Replace any
	macro_source_file->filename access by macro_source_fullname call.
	* macroscope.c (_initialize_macroscope): Update the new_macro_table
	caller.
	* macrotab.c (struct macro_table): New field comp_dir.
	(macro_include): New variables link_fullname and source_fullname.
	Replace any macro_source_file->filename access by macro_source_fullname
	call.
	(macro_lookup_inclusion): Remove the partial filenames checking code.
	(check_for_redefinition): New variables source_fullname and
	found_key_fullname.  Replace any macro_source_file->filename access by
	macro_source_fullname call.
	(macro_undef): New variables source_fullname and key_fullname.  Replace
	any macro_source_file->filename access by macro_source_fullname call.
	(macro_lookup_definition): New variables retval and source_fullname.
	Replace any macro_source_file->filename access by macro_source_fullname
	call.
	(foreach_macro): New variable key_fullname.  Replace any
	macro_source_file->filename access by macro_source_fullname call.
	(foreach_macro_in_scope): New variable datum_fullname.  Replace any
	macro_source_file->filename access by macro_source_fullname call.
	(new_macro_table): Add parameter comp_dir.  Initialize T with it.
	(macro_source_fullname): New function.
	* macrotab.h (struct macro_source_file): Extent the filename field
	comment.
	(new_macro_table): New parameter comp_dir, add a comment for it.
	(macro_source_fullname): new declaration.

gdb/testsuite/
	* gdb.linespec/base/one/header.h: New file.
	* gdb.linespec/base/two/header.h: New file.
	* gdb.linespec/macro-relative.c: New file.
	* gdb.linespec/macro-relative.exp: New file.