Closure inliner not handling keyword args correctly

[stuartarchibald]

Reporting a bug

• I am using the latest released master version of Numba (most recent is visible in
  the change log (https://github.com/numba/numba/blob/master/CHANGE_LOG).
• I have included below a minimal working reproducer (if you are unsure how
  to write one see http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports).

This:

from numba import njit
import numpy as np

@njit
def pennsylvania6():

    def foo(a, b, kw1=False):
        print(a, b, kw1)

    foo(1, 2, "x")
    foo(1, 2, kw1="y")
    foo(1, 2, kw1=True)


pennsylvania6()
print('-' * 80)
pennsylvania6.py_func()

produces:

1 2 x                                                                                                                           
1 2 False                                                                                                                       
1 2 False                                                                                                                       
--------------------------------------------------------------------------------                                                
1 2 x                                                                                                                           
1 2 y                                                                                                                           
1 2 True                                                                                                                        

suspect there's something wrong with the inliner/a missing guard against this.