* c-common.c (print_char_table): Allow 'I' flag with %d, %i and
	%u.
	(check_format_info): Support printf 'I' flag; warn about it with
	-pedantic.

testsuite:
	* gcc.dg/c99-printf-2.c, gcc.dg/format-xopen-1.c: Add some more
	tests.
	* gcc.dg/format-ext-1.c: New test.

From-SVN: r35917