clang-format: [JS] Contract fewer functions to a single line.

Before:
  var someVariable =
      function(x) { return x.zIsTooLongForOneLineWithTheDeclarationLine(); };

After:
  var someVariable = function(x) {
    return x.zIsTooLongForOneLineWithTheDeclarationLine();
  };

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@222893 91177308-0d34-0410-b5e6-96231b3b80d8