FR: CodeBlocks in REPL. #20817

$ node --version
v10.0.0

$ uname
Darwin LM-BNG-22004407 16.7.0 Darwin Kernel Version 16.7.0

$ node

> obj = {
... 
... 
... }

# If we hit the up arrow key, we see
> }

> obj = {

$ node

> obj = {
... 
... 
... }

# If we hit the up arrow key, we must see

> obj = {}