patch 9.2.0343: tests: test_clientserver may fail on slower systems

Problem:  tests: test_clientserver may fail on slower systems
Solution: Wait for argc() before checking argv() (James McCoy).

On slower systems, the argv() check may run before the server has
populated the arg list.

Add a wait for argc() to be 3 to be more tolerant of such systems

closes: #19974

Signed-off-by: James McCoy <jamessan@jamessan.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_clientserver.vim

@@ -145,6 +145,7 @@ func Test_client_server()
 
     " Edit multiple files using --remote
     call system(cmd .. ' --remote Xclientfile1 Xclientfile2 Xclientfile3')
+    call WaitForAssert({-> assert_equal('3', remote_expr(name, 'argc()'))})
     call assert_match(".*Xclientfile1\n.*Xclientfile2\n.*Xclientfile3\n", remote_expr(name, 'argv()'))
     eval name->remote_send(":%bw!\<CR>")
 

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    343,
 /**/
     342,
 /**/