PR middle-end/77475

	PR middle-end/77475
	* config/i386/i386.c (ix86_parse_stringop_strategy_string): Simplify,
	use %qs instead of %s where desirable, use argument instead of arg in
	the diagnostic wording, add list of supported strategies and
	spellcheck hint.
	(ix86_option_override_internal): Emit target("m...") instead of
	option("m...") in the diagnostic.  Use %qs instead of %s in invalid
	-march/-mtune option diagnostic.  Add list of supported arches/tunings
	and spellcheck hint.  Remove prefix, suffix and sw variables, use
	main_args_p ? "..." : "..." in diagnostics to make translation
	possible.

	* gcc.target/i386/pr65990.c: Adjust expected diagnostics.
	* gcc.dg/march-generic.c: Likewise.
	* gcc.target/i386/spellcheck-options-1.c: New test.
	* gcc.target/i386/spellcheck-options-2.c: New test.
	* gcc.target/i386/spellcheck-options-3.c: New test.
	* gcc.target/i386/spellcheck-options-4.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@240162 138bc75d-0d04-0410-961f-82ee72b054a4