Macro hygiene broken for interpolation into quoted expressions

MWE:
```julia
julia> macro foo()
           quote
               x = 1
               :($x)
           end
       end
@foo (macro with 1 method)

julia> @macroexpand @foo
quote
    #= REPL[40]:3 =#
    var"#58#x" = 1
    #= REPL[40]:4 =#
    x
end
```