repl: support hidden history file on Windows

On Windows when REPL history file has the hidden attribute node will
fail when trying to open it in 'w' mode. This changes the mode to
'r+'. The file is guaranteed to exists because of earlier open call
with 'a+'.

Fixes: https://github.com/nodejs/node/issues/5261
PR-URL: https://github.com/nodejs/node/pull/12207


Reviewed-By: James M Snell <jasnell@gmail.com>