It is otherwise impossible to determine which test failed sanitizer/valgrind
check. test/functional/helpers.lua module return was changed so that tests which
do not provide after_each function to get new check will automatically fail.
A menu item can have separate bindings for each Vim mode.
:emenu checks to see which binding it should execute. But, it assumes
it can only be called from Normal mode, so its mode detection is based
on some guesswork. For instance, it detects if you've just used C-O
and, if so, uses the Insert mode binding.
Now that :emenu can be called from any mode (via vim_command), this
commit has it check the actual mode we're in, and simply use the
binding for that mode if we aren't in Normal mode.