Mostly code cleanup: Constification.

Mostly code cleanup: Constification.

gdb/
2013-09-19  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Constification.
	* main.c (captured_main): Replace catch_command_errors by
	catch_command_errors_const.  Twice.
	* symfile.c (symbol_file_add_main_1): Make args parameter const.
	(symbol_file_add): Make name parameter const.
	(symbol_file_add_main, symbol_file_add_main_1): Make args parameter const.
	(symfile_bfd_open): Make name parameter const, rename it to cname.  Add
	variable name.  Change their usage accordingly.
	* symfile.h (symbol_file_add, symfile_bfd_open): Make first parameter
	const.
	(symbol_file_add_main): Make args parameter const.