clang-format: [JS] do not wrap after interface and type.

Summary:
`interface` and `type` are pseudo keywords and cause automatic semicolon
insertion when followed by a line break:

    interface  // gets parsed as a long variable access to "interface"
        VeryLongInterfaceName {

    }

With this change, clang-format not longer wraps after `interface` or `type`.

Reviewers: djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D30874

llvm-svn: 297605