* c-decl.c (finish_decl): When prototype with asmspec is found
	for built-in, adjust built_in_decls as well as expr.c decls.
	* expr.c (init_block_move_fn, init_block_clear_fn): New functions.
	(emit_block_move_libcall_fn, clear_storage_libcall_fn): Use it.
	* expr.c (init_block_move_fn, init_block_clear_fn): New prototypes.

	* gcc.c-torture/execute/string-opt-asm-1.c: New test.
	* gcc.c-torture/execute/string-opt-asm-2.c: New test.

From-SVN: r66181