When traversing a tree parsing for TypeScript syntax and hitting a `TSFunctionType` node, the `typeParameters` and `typeAnnotation` fields are correctly visited but the `parameters` field isn't. As a result visitors by default don't visit `foo` below:
```
var x: (foo) => void; // foo is never visited
```
```
module.exports = function() {
return {
visitor: {
Identifier(path) {
if (path.node.name == "foo") {
// Never hit because it's nested within TSFunctionType.parameters
path.node.name = "bar";
}
}
}
};
}
```
It appears to be a bug in babel-types/src/definitions/typescript.js which omits `parameters` in the visitors list for `fnOrCtr`. Fixed by adding it.
