patch 8.1.0377: xdiff doesn't use the Vim memory allocation functions

Problem:    Xdiff doesn't use the Vim memory allocation functions.
Solution:   Change the xdl_ defines.  Check for out-of-memory.  Rename
            "ignored" to "vim_ignored".
diff --git a/src/netbeans.c b/src/netbeans.c
index a753a4f..1c916b5 100644
--- a/src/netbeans.c
+++ b/src/netbeans.c
@@ -1988,10 +1988,10 @@
 	    pos = get_off_or_lnum(buf->bufp, &args);
 
 	    cp = (char *)args;
-	    ignored = (int)strtol(cp, &cp, 10);
+	    vim_ignored = (int)strtol(cp, &cp, 10);
 	    args = (char_u *)cp;
 # ifdef NBDEBUG
-	    if (ignored != -1)
+	    if (vim_ignored != -1)
 	    {
 		nbdebug(("    partial line annotation -- Not Yet Implemented!\n"));
 	    }