c-common.c (FMT_FLAG_DOLLAR_MULTIPLE): Define.

c-common.c (FMT_FLAG_DOLLAR_MULTIPLE): Define.

	* c-common.c (FMT_FLAG_DOLLAR_MULTIPLE): Define.
	(format_types): Use it for printf.
	(maybe_read_dollar_number): Add parameter for the kind of format
	involved.  Warn for multiple use for arguments if this is
	inappropriate for the kind of format involved.
	(check_format_info_main): Update calls to maybe_read_dollar_number.

testsuite:
	* gcc.dg/format-xopen-1.c: Update comments; adjust for checking
	for multiple use of arguments with scanf formats; add tests for
	multiple use of arguments.

From-SVN: r36905