`import as if`

Not sure if this is supposed to be allowed, or if it's supposed to be an error (in which case I think it would be better to error when importing).
```julia
julia> import InverseFunctions as if

julia> if.square(sqrt(2))
ERROR: ParseError:
# Error @ REPL[26]:1:3
if.square(sqrt(2))
# ╙ ── invalid identifier
Stacktrace:
[1] top-level scope
@ none:1
```