* symfile.c (set_initial_language): Update.

	* symfile.c (set_initial_language): Update.
	(deduce_language_from_filename): Argument type now const.
	* symtab.h (find_main_filename): Update.
	(deduce_language_from_filename): Update.
	* symtab.c (find_main_filename): Make result const.
	* dwarf2read.c (dw2_find_symbol_file): Change return type.
	* psymtab.c (find_symbol_file_from_partial): Change return type.
	* symfile.h (struct quick_symbol_functions) <find_symbol_file>:
	Make result const.