US109 13.04.2 p3 Non-templates may also have associated constraints

Only templates are described as having associated constraints, but [over.match.viable]/3 and 
(via [temp.constr.order]/3) [over.match.best]/2.6 need them for non-template functions.

Proposed change:
Replace "template" with "declaration"; other declarations will simply  always match one of the first two bullets.