using LegacyString breaks string(::Char)

[vtjnash]

ERROR: MethodError: string(::Char) is ambiguous. Candidates:
  string(a::Union{Char,LegacyStrings.ASCIIString,LegacyStrings.UTF8String}...) at /Users/jameson/.julia/v0.6/LegacyStrings/src/utf8.jl:161
  string(a::Union{Char,String}...) at strings/string.jl:179

[martinholters]

How about just removing string(a::Union{ByteString,Char}...)? IIUC, it's just there for performance sake, and correctness should be more important than performance. An alternative could be to rewrite it as string(a1::ByteString, a::Union{ByteString,Char}...) to keep the same performance at least for cases where the first argument is not a Char. I have no idea whether it is worth it, though.