clang-format: [JS] reserved words in method names.

Summary:
Before:
    class X {
      delete () {
        ...
      }
    }

After:
    class X {
      delete() {
        ...
      }
    }

Reviewers: djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D24804

llvm-svn: 282138