gdb

	* charset.c (iconv_open): Use UTF-16 and UTF-32, not UCS-2 and
	UCS-4.
	(iconv): Rename 'ucs_flag'.
	(GDB_DEFAULT_TARGET_WIDE_CHARSET): Use UTF-32.
	* c-lang.c (charset_for_string_type): Use UTF-16 and UTF-32, not
	UCS-2 and UCS-4.
	(convert_ucn): Use UTF-32.
gdb/testsuite
	* gdb.base/charset.exp: Use UTF-16 and UTF-32, not UCS-2 and
	UCS-4.
	* gdb.base/charset.c (utf_32_string): Rename.
	(init_utf32): Rename.
	(main): Update.