re PR c/1027 (slightly misleading printf format warning)

	PR c/1027
	* c-lang.c (c_initialize_diagnostics): Move from here ...
	* c-objc-common.c: ... to here.  Include "c-pretty-print.h".
	(c_tree_printer): Use pretty-printer to format %T.
	* c-pretty-print.c (pp_c_specifier_qualifier_list): Include space
	before '*' if not C++.
	(pp_c_direct_abstract_declarator): Don't try to print array upper
	bound for flexible array members.
	* c-tree.h: Include "diagnostic.h".
	(c_initialize_diagnostics): Declare.
	* objc/objc-lang.c (LANG_HOOKS_INITIALIZE_DIAGNOSTICS): Define.
	* c-format.c (format_type_warning): New function.  Improve
	diagnostics for incorrect format argument types.
	(check_format_types): Use it.  Add two parameters.  Use the
	TYPE_MAIN_VARIANT of wanted_type.
	(check_format_info_main): Pass new parameters to
	check_format_types.
	(struct format_wanted_type): Update comment.

testsuite:
	* gcc.dg/Wswitch-enum.c, gcc.dg/Wswitch.c,
	gcc.dg/format/branch-1.c, gcc.dg/format/diag-1.c,
	gcc.dg/format/multattr-3.c, gcc.dg/format/xopen-1.c: Update
	expected warning text.
	* gcc.dg/format/diag-2.c: New test.

From-SVN: r83965