HV-1767 Reduce the overhead of ConstraintHelper initialization in the predefined scope case

[gsmet]

https://hibernate.atlassian.net/browse/HV-1767

[yrodiere]

Looks good to me. Just a few comments about naming, but nothing critical.

[yrodiere]

annotationClassName or something like that, maybe? It's a bit hard to understand what this field stands for when reading the various methods of this class.

[yrodiere]

I'd use getBuiltinConstraints, to make the code clearer in places where this getter is called... but it's your call.

[yrodiere]

Same here, forBuiltinConstraints? Since this won't work with custom constraints.

[yrodiere]

Some nitpicking (for a change!); I usually see this pattern written that way:

		if ( jodaTimeInClassPath == null ) {
			jodaTimeInClassPath = isClassPresent( JODA_TIME_CLASS_NAME );
		}
		return jodaTimeInClassPath.booleanValue(); 

[yrodiere]

requiredConstraints or constraintDependencies or something like that? Feel free to ignore, but I had a hard time wrapping my head around this, so a more precise name might help.

[gsmet]

This is the technical term in HV but yeah I also thought about changing it to something along the lines of what you suggest so let's do it.

[gsmet]

@yrodiere I addressed your comments.