`i++` could use a better error message

I'm opening this issue based on a [question on discourse](https://discourse.julialang.org/t/compiler-complains-about-unexpected-end/83037).

Consider the following code:
```julia
i = 0
for n = 1:5
i++
end
```

This will result in (at least on Julia 1.7.0)
```julia
ERROR: syntax: unexpected "end"
```

This error message could benefit from JuliaLang/julia#45791. However, I'm doing a separate issue for this special case because a new user might write `i++` not knowing it is not equivalent to `i += 1` (or even that `++` is parsed as an infix operator). Would it be possible to have a more specific error message? Something like
```julia
ERROR: syntax: attempted to call an infix operator with just one argument - perhaps you meant "i += 1"?
```