c-format.c (check_format_info_main): Use strncmp rather than a magic prefix to handle...

c-format.c (check_format_info_main): Use strncmp rather than a magic prefix to handle multichar length specs.

gcc
	* c-format.c (check_format_info_main): Use strncmp rather than a magic prefix
	to handle multichar length specs.
	* config/i386/msformat-c.c (format_length_info ms_printf_length_specs):
	Don't prefix "I64" and "I32" with '\0'.

testsuite
	* gcc.dg/format/ms-warnI64-1.c: New file.

From-SVN: r134623