Databinding is quite slow when domain implements traits

We have observed that databinding runs quite slower when domain class implements traits.
I have attached the sample which shows the issue. Databinding runs quite slower (some time even 100% slower) on domains which implements traits.

Given a domain class

```
class City {
String name
String shortCode
String state
String country

BigDecimal latitude
BigDecimal longitude
}

@CompileStatic
trait CityTrait {
String name
String shortCode
String state
String country

BigDecimal latitude
BigDecimal longitude
}

class CityWithTrait implements CityTrait {
}

```

Given the City and CityWithTrait domain classes. The databinding the same props on CityWithTrait is quite slower compared to City.

Look at the attached example.
[perftest-bug-report-17112017.zip](https://github.com/grails/grails-core/files/1483026/perftest-bug-report-17112017.zip)

Create a runnable war, or run with bootrun.

The BootStrap runs the databinding on both of the sample domains for a million times and displays the time taken on console. Notice how slow the databinding on domain with trait it.

Bootstrap also manually sets the properties (using assignments) a 1 million time on both domains. Notice there is no big difference on how much time it takes.

So obviously it databinding which is some how getting affected by traits.

### Environment Information

- **Operating System**: OSX
- **Grails Version:** 3.2.11
- **JDK Version:** 1.8

Start with the attached performance example and its Bootstrap, which runs databinding and direct property assignments on both sample domain classes. Run it with bootrun or as a runnable WAR and compare the timings for City and CityWithTrait. Done looks like databinding no longer shows the reported slowdown for the trait-based domain.

Written by the indexing model from the issue text.