patch 9.0.0649: no indication the first line is broken for 'smoothscroll'
Problem: No indication when the first line is broken for 'smoothscroll'.
Solution: Show "<<<" in the first line.
diff --git a/src/testdir/dumps/Test_smoothscroll_5.dump b/src/testdir/dumps/Test_smoothscroll_5.dump
index 40478bb..b88bd3d 100644
--- a/src/testdir/dumps/Test_smoothscroll_5.dump
+++ b/src/testdir/dumps/Test_smoothscroll_5.dump
@@ -1,4 +1,4 @@
-|w+0&#ffffff0|o|r|d| |w|o|r|d| |w|o|r|d| |w|o|r|d| @20
+|<+0#4040ff13#ffffff0@2|d+0#0000000&| |w|o|r|d| |w|o|r|d| |w|o|r|d| @20
|l|i|n|e| |t|h|r|e@1| @29
|l|o|n|g| |w|o|r|d| |l|o|n|g| |w|o|r|d| |l|o|n|g| |w|o|r|d| |l|o|n|g| |w|o|r|d|
|l|o|n|g| |w|o|r|d| |l|o|n|g| |w|o|r|d| |l|o|n|g| |w|o|r|d| @10