vector.h: Add AST_VECTOR_SORT()

Allows a vector to be sorted in-place, rather than only during
insertion.

Change-Id: I22cba9ddf556a7e44dacc53c4431bd81dd2fa780

include/asterisk/vector.h

@@ -357,6 +357,16 @@ AST_VECTOR(ast_vector_string, char *);
 	res; \
 })
 
+/*!
+ * \brief Sort a vector in-place
+ *
+ * \param vec Vector to sort
+ * \param cmp A memcmp compatible compare function
+ */
+#define AST_VECTOR_SORT(vec, cmp) ({ \
+	qsort((vec)->elems, (vec)->current, sizeof(typeof((vec)->elems[0])), cmp); \
+})
+
 /*!
  * \brief Remove an element from a vector by index.
  *