patch 8.2.2128: there is no way to do something on CTRL-Z

Problem:    There is no way to do something on CTRL-Z.
Solution:   Add VimSuspend and VimResume autocommand events. (closes #7450)
diff --git a/src/autocmd.c b/src/autocmd.c
index a82659f..c3aa324 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -191,6 +191,8 @@
     {"WinLeave",	EVENT_WINLEAVE},
     {"VimResized",	EVENT_VIMRESIZED},
     {"TextYankPost",	EVENT_TEXTYANKPOST},
+    {"VimSuspend",	EVENT_VIMSUSPEND},
+    {"VimResume",	EVENT_VIMRESUME},
     {NULL,		(event_T)0}
 };
 
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 11e4bf5..0788fa3 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -5864,6 +5864,7 @@
     {
 	if (!eap->forceit)
 	    autowrite_all();
+	apply_autocmds(EVENT_VIMSUSPEND, NULL, NULL, FALSE, NULL);
 	windgoto((int)Rows - 1, 0);
 	out_char('\n');
 	out_flush();
@@ -5881,6 +5882,7 @@
 	scroll_start();		// scroll screen before redrawing
 	redraw_later_clear();
 	shell_resized();	// may have resized window
+	apply_autocmds(EVENT_VIMRESUME, NULL, NULL, FALSE, NULL);
     }
 }
 
diff --git a/src/normal.c b/src/normal.c
index da0ffc1..8dca538 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -5787,7 +5787,7 @@
     clearop(cap->oap);
     if (VIsual_active)
 	end_visual_mode();		// stop Visual mode
-    do_cmdline_cmd((char_u *)"st");
+    do_cmdline_cmd((char_u *)"stop");
 }
 
 /*
diff --git a/src/testdir/test_suspend.vim b/src/testdir/test_suspend.vim
index bf3f93a..327fe06 100644
--- a/src/testdir/test_suspend.vim
+++ b/src/testdir/test_suspend.vim
@@ -61,4 +61,48 @@
   call delete('Xfoo')
 endfunc
 
+func Test_suspend_autocmd()
+  CheckFeature terminal
+  CheckExecutable /bin/sh
+
+  let buf = term_start('/bin/sh', #{term_rows: 6})
+  " Wait for shell prompt.
+  call WaitForAssert({-> assert_match('[$#] $', term_getline(buf, '.'))})
+
+  call term_sendkeys(buf, v:progpath
+        \               . " --clean -X"
+        \               . " -c 'set nu'"
+        \               . " -c 'let g:count = 0'"
+        \               . " -c 'au VimSuspend * let g:count += 1'"
+        \               . " -c 'au VimResume * let g:count += 1'"
+        \               . " -c 'call setline(1, \"foo\")'"
+        \               . " Xfoo\<CR>")
+  " Cursor in terminal buffer should be on first line in spawned vim.
+  call WaitForAssert({-> assert_equal('  1 foo', term_getline(buf, '.'))})
+
+  for suspend_cmd in [":suspend\<CR>",
+        \             ":stop\<CR>",
+        \             ":suspend!\<CR>",
+        \             ":stop!\<CR>",
+        \             "\<C-Z>"]
+    " Suspend and wait for shell prompt.  Then "fg" will restore Vim.
+    call term_sendkeys(buf, suspend_cmd)
+    call CheckSuspended(buf, 0)
+  endfor
+
+  call term_sendkeys(buf, ":echo g:count\<CR>")
+  call TermWait(buf)
+  call WaitForAssert({-> assert_match('^10', term_getline(buf, 6))})
+
+  " Quit gracefully to dump coverage information.
+  call term_sendkeys(buf, ":qall!\<CR>")
+  call TermWait(buf)
+  " Wait until Vim actually exited and shell shows a prompt
+  call WaitForAssert({-> assert_match('[$#] $', term_getline(buf, '.'))})
+  call StopShellInTerminal(buf)
+
+  exe buf . 'bwipe!'
+  call delete('Xfoo')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index 1a534ee..24a8390 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2128,
+/**/
     2127,
 /**/
     2126,
diff --git a/src/vim.h b/src/vim.h
index eda0734..d6c1f46 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1344,6 +1344,8 @@
     EVENT_WINENTER,		// after entering a window
     EVENT_WINLEAVE,		// before leaving a window
     EVENT_WINNEW,		// when entering a new window
+    EVENT_VIMSUSPEND,		// before Vim is suspended
+    EVENT_VIMRESUME,		// after Vim is resumed
 
     NUM_EVENTS			// MUST be the last one
 };