Error when parsing `outer` keyword

[mjrodgers]

Currently the use of the outer keyword in a for loop is misinterpreted as the loop variable.

begin
    local i = 1
    for outer i in 1:3
        print(i)
    end
    print(i)    
end

gives (just looking at the loop)

for statement
  for binding
    identifier
    ERROR
    range expression
    [...]