patch 8.1.0379: build dependencies are incomplete

Problem:    Build dependencies are incomplete.
Solution:   Update the build dependencies, mainly for xdiff.  Adjust object
            directory for libvterm and xdiff.
diff --git a/src/version.c b/src/version.c
index 2e64eec..4dd6b65 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    379,
+/**/
     378,
 /**/
     377,