vim-patch:9.1.1937: tests: Test_matchfuzzy_initialized() fails

Problem:  tests: Test_matchfuzzy_initialized() fails
Solution: Send a dummy key (Corey Hickey)

Test_matchfuzzy_initialized seems to expect that the 'lvimgrep' will be
interrupted by sending a SIGINT. If the search finishes beforehand,
though, then the SIGINT triggers vim to tell the user how to quit.

Vim does not show this message immediately, though; instead, vim shows
the message next time it is active. When StopVimInTerminal() sends a key
sequence intended to cause vim to quit, this activates vim to show the
message instead of quitting.

I do not understand every detail of the problem fully--if I type the
characters from StopVimInTerminal() into a post-SIGTERM terminal
directly, that seems to work ok; there seems to be a timing issue due to
sending all the characters at once.

This fix does make the test work reliably for me, and the test still
works even if I limit my CPU frequency so that the search is interrupted
by the SIGINT.

fixes: vim/vim#18821
related: vim/vim#18822

https://github.com/vim/vim/commit/a3925d783af75eff0ddc99f2ee8e4ca57b5909cd

Co-authored-by: Corey Hickey <bugfood-c@fatooh.org>

test/old/testdir/test_matchfuzzy.vim

@@ -316,6 +316,13 @@ func Test_matchfuzzy_initialized()
   let job = term_getjob(buf)
   if job_status(job) == "run"
     call job_stop(job, "int")
+    " The search might or might not have been completed. If the search is
+    " finished and Vim receives a SIGINT, then that will trigger a message
+    " next time Vim is active:
+    "   Type  :qa  and press <Enter> to exit Vim
+    " If we do not send something here to trigger displaying the message, before
+    " TermWait(), then the exit sequence sent afterward does not work.
+    call term_sendkeys(buf, "\<C-O>")
     call TermWait(buf, 50)
   endif