patch 8.2.4681: build fails with a combination of features

Problem:    Build fails with a combination of features.
Solution:   Remove #ifdef for alloc_clear_id(). (John Marriott)
diff --git a/src/alloc.c b/src/alloc.c
index e6e2633..9547d67 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -180,7 +180,6 @@
     return p;
 }
 
-#if defined(FEAT_SIGNS) || defined(PROTO)
 /*
  * Same as alloc_clear() but with allocation id for testing
  */
@@ -193,7 +192,6 @@
 #endif
     return alloc_clear(size);
 }
-#endif
 
 /*
  * Allocate memory like lalloc() and set all bytes to zero.
diff --git a/src/version.c b/src/version.c
index 4e3773b..79a3bad 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4681,
+/**/
     4680,
 /**/
     4679,