re PR middle-end/78419 (ICE with target_clone on invalid target)

re PR middle-end/78419 (ICE with target_clone on invalid target)

	PR middle-end/78419
	* multiple_target.c (get_attr_len): Start with argnum and increment
	argnum on every arg.  Use strchr in a loop instead of counting commas
	manually.
	(get_attr_str): Increment argnum for every comma in the string.
	(separate_attrs): Use for instead of while loop, simplify.
	(expand_target_clones): Rename defenition argument to definition.
	Free attrs and attr_str even when diagnosing errors.  Temporarily
	change input_location around targetm.target_option.valid_attribute_p
	calls.  Don't emit warning or errors if that function fails.

	* gcc.target/i386/pr78419.c: New test.

From-SVN: r242608