added tags to test files

tests/run/args_unpacking_in_closure_T658.pyx

+# mode: run
+# tag: closures
 # ticket: 658
 
 def outer(int x, *args, **kwargs):

tests/run/closure_arg_type_error.pyx

+# mode: run
+# tag: closures
 
 # The arguments in f() are put into the closure one after the other,
 # so the reference of 'o' is filled in before the type errors are

tests/run/closure_class_T596.pyx

+# mode: run
+# tag: closures
 # ticket: 596
 
 def simple(a, b):

tests/run/closure_decorators_T478.pyx

+# mode: run
+# tag: closures
 # ticket: 478
 
 __doc__ = """

tests/run/closure_inside_cdef_T554.pyx

+# mode: run
+# tag: closures
 # ticket: 554
 
 def call_f(x):

tests/run/closure_name_mangling_T537.pyx

+# mode: run
+# tag: closures
 # ticket: 537
 
 __doc__ = u"""

tests/run/closure_self.pyx

+# mode: run
+# tag: closures
 cdef class Test:
     cdef int x
 

tests/run/closure_tests_1.pyx

+# mode: run
+# tag: closures
 #
 # closure_tests_1.pyx
 #

tests/run/closure_tests_2.pyx

+# mode: run
+# tag: closures
 #
 # closure_tests_2.pyx
 #

tests/run/closure_tests_3.pyx

+# mode: run
+# tag: closures
 #
 # closure_tests_3.pyx
 #

tests/run/closure_tests_4.pyx

+# mode: run
+# tag: closures
 #
 # closure_tests_4.pyx
 #

tests/run/closures_T82.pyx

+# mode: run
+# tag: closures
 # ticket: 82
 
 cimport cython

tests/run/list_comp_in_closure_T598.pyx

+# mode: run
+# tag: closures
 # ticket: 598
 # cython: language_level=3