patch 8.2.4065: computation overflow with large cound for :yank

Problem:    Computation overflow with large cound for :yank.
Solution:   Avoid an overflow.
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 7134359..f16f600 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -2374,7 +2374,10 @@
 	else
 	{
 	    ea.line1 = ea.line2;
-	    ea.line2 += n - 1;
+	    if (ea.line2 >= LONG_MAX - (n - 1))
+	        ea.line2 = LONG_MAX;  // avoid overflow
+	    else
+		ea.line2 += n - 1;
 	    ++ea.addr_count;
 	    /*
 	     * Be vi compatible: no error message for out of range.