Simplify switch transform test.

tests/errors/e_switch_transform.pyx

@@ -3,10 +3,10 @@
 
 import cython
 
-cdef extern from "../run/includes/switch_transform_support.h":
+cdef extern from *:
     enum:
-        ONE
-        ONE_AGAIN
+        ONE "1"
+        ONE_AGAIN "1+0"
 
 def is_not_one(int i):
     return i != ONE and i != ONE_AGAIN

tests/run/includes/switch_transform_support.h

-#ifndef SWITCH_TRANSFORM_SUPPORT_H_
-#define SWITCH_TRANSFORM_SUPPORT_H_ 1
-
-enum {
-    ONE=1,
-    ONE_AGAIN=1
-};
-
-#endif /* SWITCH_TRANSFORM_SUPPORT_H_ */

tests/run/switch_transform.pyx

 # cython: optimize.use_switch=False
 
-cdef extern from "includes/switch_transform_support.h":
+cdef extern from *:
     enum:
-        ONE
-        ONE_AGAIN
+        ONE "1"
+        ONE_AGAIN "1+0"
 
 def is_not_one(int i):
     """