IDL compiler: sync Python to r165620

Python side to:
Add overload support for non-wrapper type vs. primitive type
https://codereview.chromium.org/131973012/

BUG=239771
TBR=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/145493010

git-svn-id: svn://svn.chromium.org/blink/trunk@165696 bbb929c8-8fbe-4397-9dbb-9b2b20218538