clang-format: [JS] no ASI on `import {x as\n y}`.

Summary: ASI did not handle the ES6 `as` operator correctly.

Reviewers: djasper

Subscribers: klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D20817

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@271401 91177308-0d34-0410-b5e6-96231b3b80d8