bug in redefining modules in nested modules

[yrashk]

iex(1)> defmodule A do
...(1)>   defrecord State, a: nil
...(1)> 
...(1)>   defmodule B do
...(1)>     defrecord State, b: nil
...(1)> 
...(1)>     def a(State[b: b]), do: b
...(1)>   end
...(1)> end
iex:5: redefining module A.State
{:module,A,<<70,79,82,49,0,0,6,76,66,69,65,77,65,116,111,109,0,0,0,96,0,0,0,10,8,69,108,105,120,105,114,45,65,8,95,95,105,110,102,111,95,95,9,109,111,100,117,108,101,100,...>>,{:module,A.B,<<70,79,82,49,0,0,7,48,66,69,65,77,65,116,111,109,0,0,0,115,0,0,0,12,10,69,108,105,120,105,114,45,65,45,66,8,95,95,105,110,102,111,95,95,4,100,111,99,115,9,...>>,{:a,1}}}
iex(2)> 
nil
iex(3)> A.State.new
A.State[b: nil]
iex(4)> A.B.State.new
** (UndefinedFunctionError) undefined function: A.B.State.new/0