add path to longpath error for context

Author: IanButterworth

base/path.jl

@@ -476,7 +476,7 @@ function longpath(path::AbstractString)
         n = ccall((:GetLongPathNameW, "kernel32"), stdcall,
             UInt32, (Ptr{UInt16}, Ptr{UInt16}, UInt32),
             p, buf, length(buf))
-        windowserror(:longpath, n == 0)
+        windowserror(:longpath, n == 0, extrainfo=path)
         x = n < length(buf) # is the buffer big enough?
         resize!(buf, n) # shrink if x, grow if !x
         x && return transcode(String, buf)