IDL compiler: rename WrapperTypeInfo info => wrapperTypeInfo

|info| is used ambiguously for both PropertyCallbackInfo and
WrapperTypeInfo. It can be determined from context, but it's clearer to
just use different names.

This answers a request of haraken:
https://codereview.chromium.org/36793003/#msg4

BUG=239771

Review URL: https://codereview.chromium.org/39393004

git-svn-id: svn://svn.chromium.org/blink/trunk@160442 bbb929c8-8fbe-4397-9dbb-9b2b20218538