swift234

improve QoI for global function closing over global variable.  Where before we produced:

err.swift:5:1: error: variable '_x' captured by a closure before being initialized
get : return _x
^
err.swift:2:5: note: variable defined here
var _x : MyInt

We now produce:

t.swift:5:1: error: variable '_x' used by function definition before being initialized
get : return _x
^
t.swift:2:5: note: variable defined here
var _x : MyInt
    ^

This resolves rdar://15017114


Swift SVN r8550