restore type info in `show` of float types?

See https://github.com/JuliaLang/julia/pull/32799#issuecomment-525727486.

Before:
```
julia> Any[1.0f0, 1.0]
2-element Array{Any,1}:
 1.0f0
 1.0  
```

after:
```
julia> Any[1.0f0, 1.0]
2-element Array{Any,1}:
 1.0
 1.0
```