gdb/

gdb/
	Code cleanup.
	* breakpoint.c (clear_command): Remove variable is_abs, unify the
	call of filename_cmp with compare_filenames_for_search.
	* dwarf2read.c (dw2_map_symtabs_matching_filename): Remove variable
	is_abs, unify the call of FILENAME_CMP with
	compare_filenames_for_search.  New gdb_asserts for real_path and name.
	Unify the call of compare_filenames_for_search with FILENAME_CMP.
	* psymtab.c (partial_map_symtabs_matching_filename): Likewise.
	* symfile.h (struct quick_symbol_functions): Extend the comment for
	map_symtabs_matching_filename.
	* symtab.c (compare_filenames_for_search): Remove the function comment
	relative path requirement.  Handle absolute filenames, with a comment.
	(iterate_over_some_symtabs): Remove variable is_abs, unify the call of
	FILENAME_CMP with compare_filenames_for_search.  New gdb_asserts for
	real_path and name.  Unify the call of compare_filenames_for_search
	with FILENAME_CMP.
	(iterate_over_symtabs): New gdb_assert on REAL_PATH.

gdb/testsuite/
	* gdb.mi/mi-fullname-deleted.exp: Use double last slash for $srcfileabs.
	(compare_filenames_for_search does not match)
	(compare_filenames_for_search does match): New tests.