An extension of #11925:

I'd really like to have tab completion when setting breakpoints.  E.g.
"b MyCla<tab>" to cycle through file/classes starting with "MyCla"
"b MyClass.<tab>" to cycle through method names in MyClass
"b MyClass.foo<tab>" to cycle through methods starting with "foo"

... you get the idea.

But this is useful beyond breakpoints.  Anywhere the user might type in a file/class/method/variable name, the ability
to tab-complete will be a phenomenal timesaver.  e.g. "p MyClass.cur<tab>"