[cpp] Correctly identify preprocessor tokens vs, tokens

[AlisdairM]

Most references to tokens in [cpp] correctly refer to preprocessing tokens that a materially different thng to a regular token. This commit addresses the last few places referring to a plain token where they should instead be referring to a preprocessing token. The remining usage of plain token where evaludating the predicate to directives is intentional, and trying to change to a preproccessing token would be an actual error.