The run-time checking code did not properly convert the kind of the
argument to SYNC IMAGES, leading to an error in verify_gimple.  Fix that.

gcc/fortran/
	PR fortran/71706
	* trans-stmt.c (gfc_trans_sync): Do proper kind conversion in
	bounds-checking code.

(cherry picked from commit e6cc67f6616c96f3e18a434e0c74ba2f3818cb6d)