tests/basics: Split out specific slice tests to separate files.

So they can be automatically skipped if slice is not enabled.

tests/basics/list1.py

@@ -19,10 +19,6 @@ print(x)
 x += [2, 1]
 print(x)
 
-print(x[1:])
-print(x[:-1])
-print(x[2:3])
-
 # unsupported type on RHS of add
 try:
     [] + None

tests/basics/list_slice.py

@@ -1,6 +1,11 @@
 # test list slices, getting values
 
 x = list(range(10))
+
+print(x[1:])
+print(x[:-1])
+print(x[2:3])
+
 a = 2
 b = 4
 c = 3

tests/basics/tuple1.py

@@ -11,10 +11,6 @@ try:
 except AttributeError:
     print("AttributeError")
 
-print(x[1:])
-print(x[:-1])
-print(x[2:3])
-
 print(x + (10, 100, 10000))
 
 # inplace add operator

tests/basics/tuple_slice.py

@@ -0,0 +1,7 @@
+# tuple slicing
+
+x = (1, 2, 3 * 4)
+
+print(x[1:])
+print(x[:-1])
+print(x[2:3])