clang-format: [JS] Don't put top-level dict literals on a single line.

These are often used for enums which apparently are easier to read if
formatted with one element per line.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223367 91177308-0d34-0410-b5e6-96231b3b80d8