[C++17 DIS comment 010] [any_cons]p2, `in_place<T>` should say `in_place_type<T>`

[zygoloid]

[tkoeppe]

We also don't seem to have any library index entries for those in-place types.

[tkoeppe]

Commit in master: 2c63446

[zygoloid]

Looks good to me. Resolution: ACCEPTED.

[zygoloid]

Commit in master got rebased to 1a4e554. Merged to c++17 branch as 94e64d0.