"The type of a customization point object shall satisfy Semiregular"

[ericniebler]

Per @timsong-cpp (here), we should be testing the un-cv-qualified type of a customization point object.

Proposed Resolution

Change [customization.point.object]/p2 as follows:

-2 The type of a customization point object shall satisfy Semiregular (18.6).
+2 The type of a customization point object ignoring cv-qualifiers shall satisfy
+  Semiregular (18.6).