PR c/60197
c-family/
	* cilk.c (contains_cilk_spawn_stmt): New function.
	(contains_cilk_spawn_stmt_walker): Likewise.
	(recognize_spawn): Give error on invalid use of _Cilk_spawn.
	* c-common.h (contains_cilk_spawn_stmt): Add declaration.
c/
	* c-typeck.c (c_finish_return): Call contains_cilk_spawn_stmt instead
	of checking tree code.
cp/
	* typeck.c (check_return_expr): Call contains_cilk_spawn_stmt instead
	of checking tree code.
testsuite/
	* c-c++-common/cilk-plus/CK/pr60197.c: New test.
	* c-c++-common/cilk-plus/CK/pr60197-2.c: New test.

From-SVN: r208382