patch 8.2.3366: Vim9: debugging elseif does not stop before condition

Problem:    Vim9: debugging elseif does not stop before condition.
Solution:   Move debug statement to after the jump. (closes #8781)
diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
index 710c8ee..e7c5746 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -2255,6 +2255,53 @@
         res)
 enddef
 
+def s:DebugElseif()
+  var b = false
+  if b
+    eval 1 + 0
+  silent elseif !b
+    eval 2 + 0
+  endif
+enddef
+
+def Test_debug_elseif()
+  var res = execute('disass debug s:DebugElseif')
+  assert_match('<SNR>\d*_DebugElseif\_s*' ..
+          'var b = false\_s*' ..
+          '0 DEBUG line 1-1 varcount 0\_s*' ..
+          '1 PUSH false\_s*' ..
+          '2 STORE $0\_s*' ..
+
+          'if b\_s*' ..
+          '3 DEBUG line 2-2 varcount 1\_s*' ..
+          '4 LOAD $0\_s*' ..
+          '5 JUMP_IF_FALSE -> 10\_s*' ..
+
+          'eval 1 + 0\_s*' ..
+          '6 DEBUG line 3-3 varcount 1\_s*' ..
+          '7 PUSHNR 1\_s*' ..
+          '8 DROP\_s*' ..
+
+          'silent elseif !b\_s*' ..
+          '9 JUMP -> 20\_s*' ..
+          '10 CMDMOD silent\_s*' ..
+          '11 DEBUG line 4-4 varcount 1\_s*' ..
+          '12 LOAD $0\_s*' ..
+          '13 INVERT -1 (!val)\_s*' ..
+          '14 CMDMOD_REV\_s*' ..
+          '15 JUMP_IF_FALSE -> 20\_s*' ..
+
+          'eval 2 + 0\_s*' ..
+          '16 DEBUG line 5-5 varcount 1\_s*' ..
+          '17 PUSHNR 2\_s*' ..
+          '18 DROP\_s*' ..
+
+          'endif\_s*' ..
+          '19 DEBUG line 6-6 varcount 1\_s*' ..
+          '20 RETURN void*',
+        res)
+enddef
+
 def s:EchoMessages()
   echohl ErrorMsg | echom v:exception | echohl NONE
 enddef