patch 9.0.0657: too many #ifdefs

Problem:    Too many #ifdefs.
Solution:   Graduate the +cmdwin feature.  Now the tiny and small builds are
            equal, drop the small build.  (Martin Tournoij, closes #11268)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 5c6591c..22aa03b 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -5582,13 +5582,7 @@
 		},
 	{"cmdline_compl", 1},
 	{"cmdline_hist", 1},
-	{"cmdwin",
-#ifdef FEAT_CMDWIN
-		1
-#else
-		0
-#endif
-		},
+	{"cmdwin", 1},
 	{"comments", 1},
 	{"conceal",
 #ifdef FEAT_CONCEAL