Add value_equal
diff --git a/value.h b/value.h
index 5dfd61a..e692343 100644
--- a/value.h
+++ b/value.h
@@ -153,6 +153,11 @@
* if it isn't, <0 on error. */
int value_is_zero(struct value *val, struct value_dict *arguments);
+/* Compare two values for byte-by-byte equality. Returns >0 if they
+ * are equal, ==0 if they are not, and <0 on error. */
+int value_equal(struct value *val1, struct value *val2,
+ struct value_dict *arguments);
+
/* Convert a structure type to pointer to that structure type. */
int value_pass_by_reference(struct value *value);