PR middle-end/21024
	* builtins.c (expand_builtin_strcat): Convert the result of
	strlen to the right type.
	* fold-const.c (fold_binary) <PLUS_EXPR>: Use fold_convert to
	avoid creating type mismatches.
	<GE_EXPR>: Pass op0 and op1 to fold_build2 to avoid creating
	type mismatches.

From-SVN: r98244