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();
  };

llvm-svn: 222893