patch 9.0.0545: when a test is slow and CI times out there is no time info

Problem:    When a test is slow and CI times out there is no time info.
Solution:   Add the elapsed time to the "Executing" message.
diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index ebc692b..bb0325f 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -173,11 +173,15 @@
   return lnum - top - 1
 endfunc
 
+let g:func_start = reltime()
+
 func RunTheTest(test)
-  echoconsole 'Executing ' . a:test
+  let prefix = ''
   if has('reltime')
-    let func_start = reltime()
+    let prefix = 'took ' .. reltimestr(reltime(g:func_start)) .. '; now '
+    let g:func_start = reltime()
   endif
+  echoconsole prefix .. 'Executing ' .. a:test
 
   " Avoid stopping at the "hit enter" prompt
   set nomore
@@ -292,7 +296,7 @@
   let message = 'Executed ' . a:test
   if has('reltime')
     let message ..= repeat(' ', 50 - len(message))
-    let time = reltime(func_start)
+    let time = reltime(g:func_start)
     if reltimefloat(time) > 0.1
       let message = s:t_bold .. message
     endif